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  • 1.
    Aad, G.
    et al.
    Aix Marseille Univ, IN2P3, CNRS, CPPM, Marseille, France.
    Asimakopoulou, Eleni M.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Bergeås Kuutmann, Elin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Bokan, P.
    Georg August Univ Gottingen, Phys Inst 2, Gottingen, Germany;Uppsala Univ, Dept Phys & Astron, Uppsala, Sweden.
    Brenner, Richard
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Ekelöf, Tord
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, FREIA.
    Ellajosyula, Venugopal
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Ellert, Mattias
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Ferrari, Arnaud
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Isacson, M. F.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Martensson, M. U. F.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Zwalinski, L.
    CERN, Geneva, Switzerland.
    Measurement of the tt production cross-section and lepton differential distributions in e mu dilepton events from pp collisions at root s=13 TeV with the ATLAS detector2020In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 80, no 6, article id 528Article in journal (Refereed)
    Abstract [en]

    The inclusive top quark pair (tt<overbar></mml:mover>) production cross-section sigma tt<overbar></mml:mover> has been measured in proton-proton collisions at <mml:msqrt>s</mml:msqrt>=13<mml:mspace width="0.166667em"></mml:mspace>TeV, using 36.1 fb-1 of data collected in 2015-2016 by the ATLAS experiment at the LHC. Using events with an opposite-charge e mu pair and b-tagged jets, the cross-section is measured to be: <disp-formula id="Equ10"><mml:mtable><mml:mtr><mml:mtd columnalign="right">sigma tt<overbar></mml:mover>=826.4 +/- 3.6<mml:mspace width="0.166667em"></mml:mspace>(stat)<mml:mspace width="4pt"></mml:mspace>+/- 11.5<mml:mspace width="0.166667em"></mml:mspace>(syst)<mml:mspace width="4pt"></mml:mspace>+/- 15.7<mml:mspace width="0.166667em"></mml:mspace>(lumi)<mml:mspace width="4pt"></mml:mspace>+/- 1.9<mml:mspace width="0.166667em"></mml:mspace>(beam)<mml:mspace width="0.166667em"></mml:mspace>pb,</mml:mtd></mml:mtr></mml:mtable><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="10052_2020_7907_Article_Equ10.gif" position="anchor"></graphic></disp-formula>where the uncertainties reflect the limited size of the data sample, experimental and theoretical systematic effects, the integrated luminosity, and the LHC beam energy, giving a total uncertainty of 2.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. It is used to determine the top quark pole mass via the dependence of the predicted cross-section on mtpole, giving mtpole=173.1-2.1+2.0<mml:mspace width="0.166667em"></mml:mspace>GeV. It is also combined with measurements at <mml:msqrt>s</mml:msqrt><mml:mo>=7<mml:mspace width="0.166667em"></mml:mspace>TeV and <mml:msqrt>s</mml:msqrt><mml:mo>=8<mml:mspace width="0.166667em"></mml:mspace>TeV to derive ratios and double ratios of t<mml:mover accent="true">t<mml:mo stretchy="false"><overbar></mml:mover> and Z cross-sections at different energies. The same event sample is used to measure absolute and normalised differential cross-sections as functions of single-lepton and dilepton kinematic variables, and the results are compared with predictions from various Monte Carlo event generators.

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  • 2.
    Aaij, R.
    et al.
    Nikhef Natl Inst Subat Phys, Amsterdam, Netherlands.
    Eklund, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics. Univ Glasgow, Sch Phys & Astron, Glasgow, Lanark, Scotland.
    Zunica, G.
    Univ Manchester, Dept Phys & Astron, Manchester, Lancs, England.
    Measurement of the branching fraction of the B0-> Ds+pi- decay2021In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 81, no 4, article id 314Article in journal (Refereed)
    Abstract [en]

    A branching fraction measurement of the B0 -> Ds+</mml:msubsup>pi- decay is presented using proton-proton collision data collected with the LHCb experiment, corresponding to an integrated luminosity of 5.0<mml:mspace width="0.166667em"></mml:mspace>fb-1. The branching fraction is found to be B(B0 -> Ds+</mml:msubsup>pi-)=(19.4 +/- 1.8 +/- 1.3 +/- 1.2)x10-6, where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the B0 -> D-pi+, Ds+</mml:msubsup>-> K+K-pi+ and D--> K+pi-pi- branching fractions. This is the most precise single measurement of this quantity to date. As this decay proceeds through a single amplitude involving a b -> u charged-current transition, the result provides information on non-factorisable strong interaction effects and the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element <mml:msub>Vub. Additionally, the collision energy dependence of the hadronisation-fraction ratio <mml:msub>fs/<mml:msub>fd is measured through B<overbar></mml:mover>s0 -> Ds+pi- and B0 -> D-pi <mml:mo>+ decays.

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    FULLTEXT01
  • 3. Abarbanel, Saul
    et al.
    Ditkowski, Adi
    Gustafsson, Bertil
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    On error bounds of finite difference approximations to partial differential equations: Temporal behavior and rate of convergence2000Report (Other academic)
  • 4. Abarbanel, Saul
    et al.
    Ditkowski, Adi
    Gustafsson, Bertil
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    On error bounds of finite difference approximations to partial differential equations: Temporal behavior and rate of convergence2000In: Journal of Scientific Computing, ISSN 0885-7474, E-ISSN 1573-7691, Vol. 15, p. 79-116Article in journal (Refereed)
  • 5.
    Abbas, Qaisar
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Weak Boundary and Interface Procedures for Wave and Flow Problems2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, we have analyzed the accuracy and stability aspects of weak boundary and interface conditions (WBCs) for high order finite difference methods on Summations-By-Parts (SBP) form. The numerical technique has been applied to wave propagation and flow problems.

    The advantage of WBCs over strong boundary conditions is that stability of the numerical scheme can be proven. The boundary procedures in the advection-diffusion equation for a boundary layer problem is analyzed. By performing Navier-Stokes calculations, it is shown that most of the conclusions from the model problem carries over to the fully nonlinear case.

    The work was complemented to include the new idea of using WBCs on multiple grid points in a region, where the data is known, instead of at a single point. It was shown that we can achieve high accuracy, an increased rate of convergence to steady-state and non-reflecting boundary conditions by using this approach.

    Using the SBP technique and WBCs, we have worked out how to construct conservative and energy stable hybrid schemes for shocks using two different approaches. In the first method, we combine a high order finite difference scheme with a second order MUSCL scheme. In the second method, a procedure to locally change the order of accuracy of the finite difference schemes is developed. The main purpose is to obtain a higher order accurate scheme in smooth regions and a low order non-oscillatory scheme in the vicinity of shocks.

    Furthermore, we have analyzed the energy stability of the MUSCL scheme, by reformulating the scheme in the framework of SBP and artificial dissipation operators. It was found that many of the standard slope limiters in the MUSCL scheme do not lead to a negative semi-definite dissipation matrix, as required to get pointwise stability.

    Finally, high order simulations of shock diffracting over a convex wall with two facets were performed. The numerical study is done for a range of Reynolds numbers. By monitoring the velocities at the solid wall, it was shown that the computations were resolved in the boundary layer. Schlieren images from the computational results were obtained which displayed new interesting flow features.

    List of papers
    1. Weak versus strong no-slip boundary conditions for the Navier-Stokes equations
    Open this publication in new window or tab >>Weak versus strong no-slip boundary conditions for the Navier-Stokes equations
    2010 (English)In: Engineering Applications of Computational Fluid Mechanics, ISSN 1994-2060, Vol. 4, p. 29-38Article in journal (Refereed) Published
    National Category
    Computational Mathematics Computer Sciences
    Identifiers
    urn:nbn:se:uu:diva-112977 (URN)000276898600003 ()
    Available from: 2010-01-24 Created: 2010-01-24 Last updated: 2018-01-12Bibliographically approved
    2. A weak boundary procedure for high order finite difference approximations of hyperbolic problems
    Open this publication in new window or tab >>A weak boundary procedure for high order finite difference approximations of hyperbolic problems
    2011 (English)Report (Other academic)
    Series
    Technical report / Department of Information Technology, Uppsala University, ISSN 1404-3203 ; 2011-019
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-159353 (URN)
    Available from: 2011-09-23 Created: 2011-09-28 Last updated: 2011-11-04Bibliographically approved
    3. Accurate and stable calculations involving shocks using a new hybrid scheme
    Open this publication in new window or tab >>Accurate and stable calculations involving shocks using a new hybrid scheme
    2009 (English)In: Proc. 19th AIAA CFD Conference, AIAA , 2009Conference paper, Published paper (Refereed)
    Place, publisher, year, edition, pages
    AIAA, 2009
    Series
    Conference Proceeding Series ; 2009-3985
    National Category
    Computational Mathematics Computer Sciences
    Identifiers
    urn:nbn:se:uu:diva-110133 (URN)
    Available from: 2009-11-04 Created: 2009-11-04 Last updated: 2018-01-12Bibliographically approved
    4. A stable and conservative method for locally adapting the design order of finite difference schemes
    Open this publication in new window or tab >>A stable and conservative method for locally adapting the design order of finite difference schemes
    2011 (English)In: Journal of Computational Physics, ISSN 0021-9991, E-ISSN 1090-2716, Vol. 230, p. 4216-4231Article in journal (Refereed) Published
    National Category
    Computational Mathematics Computer Sciences
    Identifiers
    urn:nbn:se:uu:diva-134055 (URN)10.1016/j.jcp.2010.11.020 (DOI)000290185000007 ()
    Available from: 2010-11-20 Created: 2010-11-21 Last updated: 2018-01-12Bibliographically approved
    5. Energy stability of the MUSCL scheme
    Open this publication in new window or tab >>Energy stability of the MUSCL scheme
    2010 (English)In: Numerical Mathematics and Advanced Applications: 2009, Berlin: Springer-Verlag , 2010, p. 61-68Conference paper, Published paper (Refereed)
    Place, publisher, year, edition, pages
    Berlin: Springer-Verlag, 2010
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-132925 (URN)10.1007/978-3-642-11795-4_5 (DOI)000395207900005 ()978-3-642-11794-7 (ISBN)
    Available from: 2010-10-29 Created: 2010-10-29 Last updated: 2018-06-16Bibliographically approved
    6. The Effect of Reynolds Number in High Order Accurate Calculations with Shock Diffraction
    Open this publication in new window or tab >>The Effect of Reynolds Number in High Order Accurate Calculations with Shock Diffraction
    2010 (English)In: Proc. 7th South African Conference on Computational and Applied Mechanics, South African Association for Theoretical and Applied Mechanics , 2010, p. 416-423Conference paper, Published paper (Refereed)
    Place, publisher, year, edition, pages
    South African Association for Theoretical and Applied Mechanics, 2010
    National Category
    Computational Mathematics Computer Sciences
    Identifiers
    urn:nbn:se:uu:diva-113571 (URN)978-0-620-49192-1 (ISBN)
    Available from: 2010-01-29 Created: 2010-01-29 Last updated: 2018-01-12Bibliographically approved
    Download full text (pdf)
    fulltext
  • 6.
    Abbas, Qaisar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Nordström, Jan
    A weak boundary procedure for high order finite difference approximations of hyperbolic problems2011Report (Other academic)
  • 7.
    Abbas, Qaisar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Nordström, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Weak versus strong no-slip boundary conditions for the Navier-Stokes equations2010In: Engineering Applications of Computational Fluid Mechanics, ISSN 1994-2060, Vol. 4, p. 29-38Article in journal (Refereed)
  • 8.
    Abbas, Qaisar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Nordström, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Weak versus Strong No-Slip Boundary Conditions for the Navier-Stokes Equations2008In: Proc. 6th South African Conference on Computational and Applied Mechanics, South African Association for Theoretical and Applied Mechanics , 2008, p. 52-62Conference paper (Other academic)
  • 9.
    Abbas, Qaisar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    van der Weide, Edwin
    Nordström, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Accurate and stable calculations involving shocks using a new hybrid scheme2009In: Proc. 19th AIAA CFD Conference, AIAA , 2009Conference paper (Refereed)
  • 10.
    Abbas, Qaisar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    van der Weide, Edwin
    Nordström, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Energy stability of the MUSCL scheme2010In: Numerical Mathematics and Advanced Applications: 2009, Berlin: Springer-Verlag , 2010, p. 61-68Conference paper (Refereed)
  • 11.
    Abdalmoaty, Mohamed
    KTH, Reglerteknik.
    Learning Stochastic Nonlinear Dynamical Systems Using Non-stationary Linear Predictors2017Licentiate thesis, monograph (Other academic)
    Abstract [en]

    The estimation problem of stochastic nonlinear parametric models is recognized to be very challenging due to the intractability of the likelihood function. Recently, several methods have been developed to approximate the maximum likelihood estimator and the optimal mean-square error predictor using Monte Carlo methods. Albeit asymptotically optimal, these methods come with several computational challenges and fundamental limitations.

    The contributions of this thesis can be divided into two main parts. In the first part, approximate solutions to the maximum likelihood problem are explored. Both analytical and numerical approaches, based on the expectation-maximization algorithm and the quasi-Newton algorithm, are considered. While analytic approximations are difficult to analyze, asymptotic guarantees can be established for methods based on Monte Carlo approximations. Yet, Monte Carlo methods come with their own computational difficulties; sampling in high-dimensional spaces requires an efficient proposal distribution to reduce the number of required samples to a reasonable value.

    In the second part, relatively simple prediction error method estimators are proposed. They are based on non-stationary one-step ahead predictors which are linear in the observed outputs, but are nonlinear in the (assumed known) input. These predictors rely only on the first two moments of the model and the computation of the likelihood function is not required. Consequently, the resulting estimators are defined via analytically tractable objective functions in several relevant cases. It is shown that, under mild assumptions, the estimators are consistent and asymptotically normal. In cases where the first two moments are analytically intractable due to the complexity of the model, it is possible to resort to vanilla Monte Carlo approximations. Several numerical examples demonstrate a good performance of the suggested estimators in several cases that are usually considered challenging.

  • 12.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Mahata, Pritha
    Mayr, Richard
    Dense-Timed Petri Nets: Checking Zenoness, Token liveness and Boundedness2007In: Logical Methods in Computer Science, ISSN 1860-5974, E-ISSN 1860-5974, Vol. 3, no 1, p. 1-61Article in journal (Refereed)
    Abstract [en]

    We consider Dense-Timed Petri Nets (TPN), an extension of Petri nets in which each token is equipped with a real-valued clock and where the semantics is lazy (i.e., enabled transitions need not fire; time can pass and disable transitions). We consider the following verification problems for TPNs. (i) Zenoness: whether there exists a zeno-computation from a given marking, i.e., an infinite computation which takes only a finite amount of time. We show decidability of zenoness for TPNs, thus solving an open problem from [Escrig et al.]. Furthermore, the related question if there exist arbitrarily fast computations from a given marking is also decidable. On the other hand, universal zenoness, i.e., the question if all infinite computations from a given marking are zeno, is undecidable. (ii) Token liveness: whether a token is alive in a marking, i.e., whether there is a computation from the marking which eventually consumes the token. We show decidability of the problem by reducing it to the coverability problem, which is decidable for TPNs. (iii) Boundedness: whether the size of the reachable markings is bounded. We consider two versions of the problem; namely semantic boundedness where only live tokens are taken into consideration in the markings, and syntactic boundedness where also dead tokens are considered. We show undecidability of semantic boundedness, while we prove that syntactic boundedness is decidable through an extension of the Karp-Miller algorithm.

  • 13.
    Abdulle, Assyr
    et al.
    Institute of Mathematics, École Polytechnique Fédérale de Lausanne, Station 8, Lausanne,CH-1015, Switzerland.
    Arjmand, Doghonay
    Institute of Mathematics, École Polytechnique Fédérale de Lausanne, Station 8, Lausanne,CH-1015, Switzerland.
    Paganoni, Edoardo
    Institute of Mathematics, École Polytechnique Fédérale de Lausanne, Station 8, Lausanne,CH-1015, Switzerland.
    A parabolic local problem with exponential decay of the resonance error for numerical homogenization2021In: Mathematical Models and Methods in Applied Sciences, ISSN 0218-2025, Vol. 31, no 13, p. 2733-2772Article in journal (Refereed)
    Abstract [en]

    This paper aims at an accurate and efficient computation of effective quantities, e.g. the homogenized coefficients for approximating the solutions to partial differential equations with oscillatory coefficients. Typical multiscale methods are based on a micro–macro-coupling, where the macromodel describes the coarse scale behavior, and the micromodel is solved only locally to upscale the effective quantities, which are missing in the macromodel. The fact that the microproblems are solved over small domains within the entire macroscopic domain, implies imposing artificial boundary conditions on the boundary of the microscopic domains. A naive treatment of these artificial boundary conditions leads to a first-order error in 𝜀/𝛿𝜀/δ, where 𝜀<𝛿𝜀<δ represents the characteristic length of the small scale oscillations and 𝛿𝑑δd is the size of microdomain. This error dominates all other errors originating from the discretization of the macro and the microproblems, and its reduction is a main issue in today’s engineering multiscale computations. The objective of this work is to analyze a parabolic approach, first announced in A. Abdulle, D. Arjmand, E. Paganoni, C. R. Acad. Sci. Paris, Ser. I, 2019, for computing the homogenized coefficients with arbitrarily high convergence rates in 𝜀/𝛿𝜀/δ. The analysis covers the setting of periodic microstructure, and numerical simulations are provided to verify the theoretical findings for more general settings, e.g. non-periodic microstructures.

  • 14.
    Abdulle, Assyr
    et al.
    Ecole Polytech Fed Lausanne, Inst Math, ANMC, Stn 8, Lausanne, Switzerland..
    Arjmand, Doghonay
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis. Ecole Polytech Fed Lausanne, Inst Math, ANMC, Stn 8, Lausanne, Switzerland..
    Paganoni, Edoardo
    Ecole Polytech Fed Lausanne, Inst Math, ANMC, Stn 8, Lausanne, Switzerland..
    AN ELLIPTIC LOCAL PROBLEM WITH EXPONENTIAL DECAY OF THE RESONANCE ERROR FOR NUMERICAL HOMOGENIZATION2023In: Multiscale Modeling & simulation, ISSN 1540-3459, E-ISSN 1540-3467, Vol. 21, no 2, p. 513-541Article in journal (Refereed)
    Abstract [en]

    Numerical multiscale methods usually rely on some coupling between a macroscopic and a microscopic model. The macroscopic model is incomplete as effective quantities, such as the homogenized material coefficients or fluxes, are missing in the model. These effective data need to be computed by running local microscale simulations followed by a local averaging of the microscopic information. Motivated by the classical homogenization theory, it is a common practice to use local elliptic cell problems for computing the missing homogenized coefficients in the macro model. Such a consideration results in a first order error O(E/8), where E represents the wavelength of the microscale variations and 8 is the size of the microscopic simulation boxes. This error, called ``resonance error,"" originates from the boundary conditions used in the microproblem and typically dominates all other errors in a multiscale numerical method. Optimal decay of the resonance error remains an open problem, although several interesting approaches reducing the effect of the boundary have been proposed over the last two decades. In this paper, as an attempt to resolve this problem, we propose a computationally efficient, fully elliptic approach with exponential decay of the resonance error.

  • 15. Abdulle, Assyr
    et al.
    Arjmand, Doghonay
    Paganoni, Edoardo
    Exponential decay of the resonance error in numerical homogenization via parabolic and elliptic cell problems2019In: Comptes rendus. Mathematique, ISSN 1631-073X, E-ISSN 1778-3569, Vol. 357, no 6, p. 545-551Article in journal (Refereed)
    Abstract [en]

    This paper presents two new approaches for finding the homogenized coefficients of multiscale elliptic PDEs. Standard approaches for computing the homogenized coefficients suffer from the so-called resonance error, originating from a mismatch between the true and the computational boundary conditions. Our new methods, based on solutions of parabolic and elliptic cell problems, result in an exponential decay of the resonance error.

  • 16.
    Abenius, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Direct and Inverse Methods for Waveguides and Scattering Problems in the Time Domain2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Numerical simulation is an important tool in understanding the electromagnetic field and how it interacts with the environment. Different topics for time-domain finite-difference (FDTD) and finite-element (FETD) methods for Maxwell's equations are treated in this thesis.

    Subcell models are of vital importance for the efficient modeling of small objects that are not resolved by the grid. A novel model for thin sheets using shell elements is proposed. This approach has the advantage of taking into account discontinuities in the normal component of the electric field, unlike previous models based on impedance boundary conditions (IBCs). Several results are presented to illustrate the capabilities of the shell element approach.

    Waveguides are of fundamental importance in many microwave applications, for example in antenna feeds. The key issues of excitation and truncation of waveguides are addressed. A complex frequency shifted form of the uniaxial perfectly matched layer (UPML) absorbing boundary condition (ABC) in FETD is developed. Prism elements are used to promote automatic grid generation and enhance the performance. Results are presented where reflection errors below -70dB are obtained for different types of waveguides, including inhomogeneous cases. Excitation and analysis via the scattering parameters are achieved using waveguide modes computed by a general frequency-domain mode solver for the vector Helmholtz equation. Huygens surfaces are used in both FDTD and FETD for excitation in waveguide ports.

    Inverse problems have received an increased interest due to the availability of powerful computers. An important application is non-destructive evaluation of material. A time-domain, minimization approach is presented where exact gradients are computed using the adjoint problem. The approach is applied to a general form of Maxwell's equations including dispersive media and UPML. Successful reconstruction examples are presented both using synthetic and experimental measurement data. Parameter reduction of complex geometries using simplified models is an interesting topic that leads to an inverse problem. Gradients for subcell parameters are derived and a successful reconstruction example is presented for a combined dielectric sheet and slot geometry.

    List of papers
    1. Hybrid time domain solvers for the Maxwell equations in 2D
    Open this publication in new window or tab >>Hybrid time domain solvers for the Maxwell equations in 2D
    Show others...
    2002 (English)In: International Journal for Numerical Methods in Engineering, ISSN 0029-5981, E-ISSN 1097-0207, Vol. 53, p. 2185-2199Article in journal (Refereed) Published
    National Category
    Computational Mathematics Computer Sciences
    Identifiers
    urn:nbn:se:uu:diva-44333 (URN)10.1002/nme.380 (DOI)
    Projects
    GEMS
    Available from: 2007-01-26 Created: 2007-01-26 Last updated: 2018-01-11Bibliographically approved
    2. Waveguide Truncation Using UPML in the Finite-Element Time-Domain Method
    Open this publication in new window or tab >>Waveguide Truncation Using UPML in the Finite-Element Time-Domain Method
    2005 (English)Report (Other academic)
    Series
    Technical report / Department of Information Technology, Uppsala University, ISSN 1404-3203 ; 2005-026
    National Category
    Computational Mathematics
    Identifiers
    urn:nbn:se:uu:diva-80256 (URN)
    Projects
    GEMS
    Available from: 2007-02-03 Created: 2007-02-03 Last updated: 2014-09-03Bibliographically approved
    3. Solving inverse electromagnetic problems using FDTD and gradient-based minimization
    Open this publication in new window or tab >>Solving inverse electromagnetic problems using FDTD and gradient-based minimization
    2006 (English)In: International Journal for Numerical Methods in Engineering, ISSN 0029-5981, E-ISSN 1097-0207, Vol. 68, p. 650-673Article in journal (Refereed) Published
    National Category
    Computational Mathematics Computer Sciences
    Identifiers
    urn:nbn:se:uu:diva-80802 (URN)10.1002/nme.1731 (DOI)000241713800003 ()
    Projects
    GEMS
    Available from: 2007-01-26 Created: 2007-01-26 Last updated: 2018-01-13Bibliographically approved
    4. Thin Sheet Modeling Using Shell Elements in the Finite-Element Time-Domain Method
    Open this publication in new window or tab >>Thin Sheet Modeling Using Shell Elements in the Finite-Element Time-Domain Method
    2006 (English)In: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221, Vol. 54, p. 28-34Article in journal (Refereed) Published
    National Category
    Computational Mathematics Computer Sciences
    Identifiers
    urn:nbn:se:uu:diva-80325 (URN)10.1109/TAP.2005.861554 (DOI)000235016700004 ()
    Projects
    GEMS
    Available from: 2007-01-26 Created: 2007-01-26 Last updated: 2018-01-13Bibliographically approved
    5. Modeling of inhomogeneous waveguides using hybrid methods
    Open this publication in new window or tab >>Modeling of inhomogeneous waveguides using hybrid methods
    2005 (English)Manuscript (preprint) (Other academic)
    National Category
    Computational Mathematics Computer Sciences
    Identifiers
    urn:nbn:se:uu:diva-93590 (URN)
    Projects
    GEMS
    Available from: 2005-10-11 Created: 2005-10-11 Last updated: 2018-01-13Bibliographically approved
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  • 17. Abenius, Erik
    et al.
    Andersson, Ulf
    Edelvik, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Eriksson, Lasse
    Ledfelt, Gunnar
    Hybrid time domain solvers for the Maxwell equations in 2D2002In: International Journal for Numerical Methods in Engineering, ISSN 0029-5981, E-ISSN 1097-0207, Vol. 53, p. 2185-2199Article in journal (Refereed)
  • 18.
    Abenius, Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Edelvik, Fredrik
    Thin Sheet Modeling Using Shell Elements in the Finite-Element Time-Domain Method2006In: IEEE Transactions on Antennas and Propagation, ISSN 0018-926X, E-ISSN 1558-2221, Vol. 54, p. 28-34Article in journal (Refereed)
  • 19.
    Abenius, Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Edelvik, Fredrik
    Johansson, Christer
    Waveguide Truncation Using UPML in the Finite-Element Time-Domain Method2005Report (Other academic)
  • 20.
    Abenius, Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Johansson, Christer
    A General Approach for Time-Domain Simulation of Waveguides in 3D2004In: Proc. EMB 04, Computational Electromagnetics: Methods and Applications, Göteborg, Sweden: Department of Electromagnetics, Chalmers University of Technology , 2004, p. 220-226Conference paper (Other academic)
  • 21.
    Abenius, Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Johansson, Christer
    Modeling of inhomogeneous waveguides using hybrid methods2005Manuscript (preprint) (Other academic)
  • 22.
    Abenius, Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Strand, Bo
    Solving inverse electromagnetic problems using FDTD and gradient-based minimization2006In: International Journal for Numerical Methods in Engineering, ISSN 0029-5981, E-ISSN 1097-0207, Vol. 68, p. 650-673Article in journal (Refereed)
  • 23. Abenius, Erik
    et al.
    Strand, Bo
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Alestra, Stephane
    Inverse Electromagnetic Scattering Using the Finite-Difference Time-Domain Method2000In: Proc. Millennium Conference on Antennas and Propagation, Noordwijk, The Netherlands: ESA Publications , 2000, p. 4-Conference paper (Refereed)
  • 24.
    Ablikim, M.
    et al.
    Inst High Energy Phys, Beijing 100049, Peoples R China.
    Adlarson, Patrik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Biernat, Jacek
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Ikegami Andersson, Walter
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Johansson, Tord
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Kupsc, Andrzej
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Li, Cui
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Papenbrock, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Schönning, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Wolke, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Zou, J. H.
    Inst High Energy Phys, Beijing 100049, Peoples R China.
    Observation of X(2370) and search for X(2120) in J/psi ->gamma KKeta': BESIII Collaboration2020In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 80, no 8, article id 746Article in journal (Refereed)
    Abstract [en]

    Using a sample of 1.31x109<mml:mspace width="3.33333pt"></mml:mspace>J/psi events collected with the BESIII detector, we perform a study of J/psi -> gamma KK<overbar></mml:mover>eta '. X(2370) is observed in the KK<overbar></mml:mover>eta ' invariant-mass distribution with a statistical significance of 8.3 sigma. Its resonance parameters are measured to be M=2341.6 +/- 6.5<mml:mspace width="0.166667em"></mml:mspace>(stat.)+/- 5.7<mml:mspace width="0.166667em"></mml:mspace>(syst.)<mml:mspace width="3.33333pt"></mml:mspace>MeV/c2 and Gamma =117 +/- 10<mml:mspace width="0.166667em"></mml:mspace>(stat.)+/- 8<mml:mspace width="0.166667em"></mml:mspace>(syst.)<mml:mspace width="3.33333pt"></mml:mspace>MeV. The product branching fractions for J/psi -> gamma X(2370),X(2370)-> K+K-eta ' and J/psi -> gamma X(2370),X(2370)-> KS0KS0 eta ' are determined to be (1.79 +/- 0.23<mml:mspace width="0.166667em"></mml:mspace>(stat.)+/- 0.65<mml:mspace width="0.166667em"></mml:mspace>(syst.))x10-5 and (1.18 +/- 0.32<mml:mspace width="0.166667em"></mml:mspace>(stat.)+/- 0.39<mml:mspace width="0.166667em"></mml:mspace>(syst.))x10-5, respectively. No evident signal for X(2120) is observed in the KK<overbar></mml:mover>eta ' invariant-mass distribution. The upper limits for the product branching fractions of B(J/psi -> gamma X(2120)-> gamma K+K-eta ') and B(J/psi -> gamma X(2120)-> gamma KS0KS0 eta ') are determined to be 1.49x10<mml:mo>-5 and 6.38<mml:mo>x10<mml:mo>-6 at the 90% confidence level, respectively.

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  • 25.
    Ablikim, M.
    et al.
    Inst High Energy Phys, Beijing 100049, Peoples R China.
    Adlarson, Patrik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Johansson, Tord
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Kupsc, Andrzej
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics. Natl Ctr Nucl Res, PL-02093 Warsaw, Poland.
    Schönning, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Thorén, Viktor
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Wolke, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Zu, J.
    State Key Lab Particle Detect & Elect, Beijing 100049, Peoples R China;State Key Lab Particle Detect & Elect, Hefei 230026, Peoples R China;Univ Sci & Technol China, Hefei 230026, Peoples R China.
    Measurement of the branching fraction for the decay ψ(3686)→ϕKS0KS02023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 5, article id 052001Article in journal (Refereed)
    Abstract [en]

    Based on (448.1±2.9)×106 ψ(3686) events collected with the BESIII detector operating at the BEPCII collider, the decay ψ(3686)→ϕK0SK0S is observed for the first time. Taking the interference between ψ(3686) decay and continuum production into account, the branching fraction of this decay is measured to be B(ψ(3686)→ϕK0SK0S)=(3.53±0.20±0.21)×10−5, where the first uncertainty is statistical and the second is systematic. Combining with the world average value for B(J/ψ→ϕK0SK0S), the ratio B(ψ(3686)→ϕK0SK0S)/B(J/ψ→ϕK0SK0S) is determined to be (6.0±1.6)%, which is suppressed relative to the 12% rule.

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  • 26.
    Abodayeh, Kamaleldin
    et al.
    Prince Sultan Univ, Dept Math & Gen Sci, Riyadh, Saudi Arabia.
    Raza, Ali
    Air Univ, Dept Math, Stochat Anal & Optimizat Res Grp, PAF Complex E-9, Islamabad 44000, Pakistan.
    Arif, Muhammad Shoaib
    Air Univ, Dept Math, Stochat Anal & Optimizat Res Grp, PAF Complex E-9, Islamabad 44000, Pakistan.
    Rafiq, Muhammad
    Univ Cent Punjab, Fac Engn, Lahore, Pakistan.
    Bibi, Mairaj
    Comsats Univ, Dept Math, Chak Shahzad Campus Pk Rd, Islamabad, Pakistan.
    Mohsin, Muhammad
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    Stochastic Numerical Analysis for Impact of Heavy Alcohol Consumption on Transmission Dynamics of Gonorrhoea Epidemic2020In: Computers, Materials and Continua, ISSN 1546-2218, E-ISSN 1546-2226, Vol. 62, no 3, p. 1125-1142Article in journal (Refereed)
    Abstract [en]

    This paper aims to perform a comparison of deterministic and stochastic models. The stochastic modelling is a more realistic way to study the dynamics of gonorrhoea infection as compared to its corresponding deterministic model. Also, the deterministic solution is itself mean of the stochastic solution of the model. For numerical analysis, first, we developed some explicit stochastic methods, but unfortunately, they do not remain consistent in certain situations. Then we proposed an implicitly driven explicit method for stochastic heavy alcohol epidemic model. The proposed method is independent of the choice of parameters and behaves well in all scenarios. So, some theorems and simulations are presented in support of the article.

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    fulltext
  • 27.
    Aboud, Mathilde
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Algebra and Geometry.
    Philosophy of mathematics in “La Science et l’Hypothèse”, from Henri Poincaré.2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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    fulltext
  • 28.
    Abouzaid, Mohammed
    et al.
    Columbia Univ, Dept Math, 2990 Broadway,MC 4406, New York, NY 10027 USA.;Stanford Univ, Dept Math, Bldg 380, Stanford, CA 94305 USA.
    Diogo, Luis
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    Monotone Lagrangians in cotangent bundles of spheres2023In: Advances in Mathematics, ISSN 0001-8708, E-ISSN 1090-2082, Vol. 427, article id 109114Article in journal (Refereed)
    Abstract [en]

    We study the compact monotone Fukaya category of T*Sn, for n & GE; 2, and show that it is split-generated by two classes of objects: the zero-section Sn (equipped with suitable bounding cochains) and a 1-parameter family of monotone Lagrangian tori (S1 x Sn-1)& tau;, with monotonicity constants & tau; > 0 (equipped with rank 1 unitary local systems). As a consequence, any closed orientable spin monotone Lagrangian (possibly equipped with auxiliary data) with non-trivial Floer cohomology is non-displaceable from either Sn or one of the (S1 x Sn-1)& tau;. In the case of T*S3, the monotone Lagrangians (S1 x S2)& tau; can be replaced by a family of monotone tori T & tau;3.& COPY.

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    fulltext
  • 29.
    Abouzaid, Mohammed
    et al.
    Columbia Univ, Dept Math, New York, NY 10027 USA.
    Kragh, Thomas
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Algebra and Geometry.
    On the immersion classes of nearby Lagrangians2016In: Journal of Topology, ISSN 1753-8416, E-ISSN 1753-8424, Vol. 9, no 1, p. 232-244Article in journal (Refereed)
    Abstract [en]

    We show that the transfer map on Floer homotopy types associated to an exact Lagrangian embedding is an equivalence. This provides an obstruction to representing isotopy classes of Lagrangian immersions by Lagrangian embeddings, which, unlike previous obstructions, is sensitive to information that cannot be detected by Floer cochains. We show this by providing a concrete computation in the case of spheres.

  • 30.
    Abouzaid, Mohammed
    et al.
    Columbia Univ, Dept Math, Room 509,MC 4406 2990 Broadway, New York, NY 10027 USA.
    Kragh, Thomas
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Algebra and Geometry.
    Simple homotopy equivalence of nearby Lagrangians2018In: Acta Mathematica, ISSN 0001-5962, E-ISSN 1871-2509, Vol. 220, no 2, p. 207-237Article in journal (Refereed)
    Abstract [en]

    Given a closed exact Lagrangian in the cotangent bundle of a closed smooth manifold, we prove that the projection to the base is a simple homotopy equivalence.

  • 31.
    Abou-Zeid, M.
    et al.
    Georg August Univ Gottingen, SUB, Pl Gottinger Sieben 1, D-37073 Gottingen, Germany.
    Hull, C. M.
    Imperial Coll London, Blackett Lab, Theory Grp, Prince Consort Rd, London SW7 2AZ, England.
    Lindström, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics. Imperial Coll London, Blackett Lab, Theory Grp, Prince Consort Rd, London SW7 2AZ, England.
    Rocek, M.
    SUNY Stony Brook, CN Yang Inst Theoret Phys, Stony Brook, NY 11794 USA.
    T-duality in (2,1) superspace2019In: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, no 6, article id 138Article in journal (Refereed)
    Abstract [en]

    We find the T-duality transformation rules for 2-dimensional (2,1) supersymmetric sigma-models in (2,1) superspace. Our results clarify certain aspects of the (2,1) sigma model geometry relevant to the discussion of T-duality. The complexified duality transformations we find are equivalent to the usual Buscher duality transformations (including an important refinement) together with diffeomorphisms. We use the gauging of sigma-models in (2,1) superspace, which we review and develop, finding a manifestly real and geometric expression for the gauged action. We discuss the obstructions to gauging (2,1) sigma-models, and find that the obstructions to (2,1) T-duality are considerably weaker.

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  • 32.
    Abrahamsson, Leif R.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    A priori estimates for solutions of singular perturbations with a turning point1977In: Studies in applied mathematics (Cambridge), ISSN 0022-2526, E-ISSN 1467-9590, Vol. 56, p. 51-69Article in journal (Refereed)
  • 33.
    Abrahamsson, Leif R.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Keller, Herbert B.
    Kreiss, Heinz-Otto
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Difference approximations for singular perturbations of systems of ordinary differential equations1974In: Numerische Mathematik, ISSN 0029-599X, E-ISSN 0945-3245, Vol. 22, p. 367-391Article in journal (Refereed)
  • 34.
    Abrahamsson, Linda
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Mathematical Statistics.
    Statistical models of breast cancer tumour growth for mammography screening data2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
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  • 35.
    Abrahamsson, Per Anders
    et al.
    Uppsala University, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Faculty of Social Sciences, Department of Information Science. Uppsala University, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Faculty of Social Sciences, Department of Information Science.
    Adami, Hans Olov
    Taube, Adam
    Kim, KyungMann
    Zelen, Marvin
    Kulldorff, Martin
    Re: Long-term survival and mortality in prostate cancer treated with noncurative intent1995In: UROLGY, Vol. 154, p. 460-465Article in journal (Refereed)
  • 36. Abramovic, A.
    et al.
    Pecaric, J.
    Persson, Lars-Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Applied mathematics.
    Varosanec, S.
    General inequalities via isotonic subadditive functionals2007In: Mathematical Inequalities & Applications, ISSN 1331-4343, E-ISSN 1848-9966, Vol. 10, no 1, p. 15-28Article in journal (Refereed)
    Abstract [en]

    In this manuscript a number of general inequalities for isotonic subadditive functionals on a set of positive mappings are proved and applied. In particular, it is pointed out that these inequalities both unify and generalize some general forms of the Hö̈lder, Popoviciu, Minkowski, Bellman and Power mean inequalities. Also some refinements of some of these results are proved.

  • 37. Aceto, Lidia
    et al.
    Mazza, Mariarosa
    Serra-Capizzano, Stefano
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Scientific Computing. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Numerical Analysis.
    Fractional Laplace operator in two dimensions, approximating matrices, and related spectral analysis2020In: Calcolo, ISSN 0008-0624, E-ISSN 1126-5434, Vol. 57, article id 27Article in journal (Refereed)
  • 38.
    Aceto, Paolo
    et al.
    Alfred Renyi Inst Math, 13-15 Realtanoda U, H-1053 Budapest, Hungary..
    Golla, Marco
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Algebra and Geometry.
    Dehn surgeries and rational homology2017In: Algebraic and Geometric Topology, ISSN 1472-2747, E-ISSN 1472-2739, Vol. 17, no 1, p. 487-527Article in journal (Refereed)
    Abstract [en]

    We consider the question of which Dehn surgeries along a given knot bound rational homology balls. We use Ozsvath and Szabo's correction terms in Heegaard Floer homology to obtain general constraints on the surgery coefficients. We then turn our attention to the case of integral surgeries, with particular emphasis on positive torus knots. Finally, combining these results with a lattice-theoretic obstruction based on Donaldson's theorem, we classify which integral surgeries along torus knots of the form Tkq 1; q bound rational homology balls.

  • 39.
    Aceto, Paolo
    et al.
    Alfred Renyi Inst Math, Realtanoda Ut 13-15, H-1053 Budapest, Hungary..
    Golla, Marco
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    Larson, Kyle
    Michigan State Univ, Dept Math, 619 Red Cedar Rd, E Lansing, MI 48824 USA..
    Embedding 3-manifolds in spin 4-manifolds2017In: Journal of Topology, ISSN 1753-8416, E-ISSN 1753-8424, Vol. 10, no 2, p. 301-323Article in journal (Refereed)
    Abstract [en]

    An invariant of orientable 3-manifolds is defined by taking the minimum n such that a given 3-manifold embeds in the connected sum of n copies of S-2 x S-2, and we call this n the embedding number of the 3-manifold. We give some general properties of this invariant, and make calculations for families of lens spaces and Brieskorn spheres. We show how to construct rational and integral homology spheres whose embedding numbers grow arbitrarily large, and which can be calculated exactly if we assume the 11/8-Conjecture. In a different direction we show that any simply connected 4-manifold can be split along a rational homology sphere into a positive definite piece and a negative definite piece.

  • 40.
    Achcar, JA
    et al.
    Uppsala University, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Faculty of Social Sciences, Department of Information Science.
    Agrawal, MC
    Anand, KN
    Ali, MM
    Ali, MM
    Bagui, SC
    Baker, RD
    Balamurali, S
    Balasooriya, U
    Bansal, AK
    Barry, J
    Bonett, DG
    Box, G
    Carling, K
    Caudill, SB
    Chakraborti, S
    Chatfield, C
    Chatterjee, S
    Cornell, JA
    Cox, D
    Draper, NR
    Ehrenberg, A
    Finney, DJ
    25 years of applied statistics1998In: JOURNAL OF APPLIED STATISTICS, ISSN 0266-4763, Vol. 25, no 1, p. 3-22Article in journal (Refereed)
  • 41. Aczel, Peter
    et al.
    Crosilla, Laura
    Ishihara, Hajime
    Palmgren, Erik
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Mathematics. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Mathematics, Mathematical Logic.
    Schuster, Peter
    Binary refinement implies discrete exponentiation2006In: Studia Logica, Vol. 84, p. 361-368Article in journal (Refereed)
  • 42.
    Adabanian, Jakob
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Dynamical Systems and Number Theory.
    Euklides och primtal2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I denna uppsats presenteras några av Euklides upptäckter inom matematikenmed fokus på talteori och i synnerhet primtal. Dessa upptäckter har haft stor betydelse för dagens matematik - men tas ibland för givna och ses som självklara. Vi kommer att se närmare på  några av Euklides upptäckter för att diskutera hur de såg ut då och hur de ser ut idag, medfokus på den matematiska teorin.

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  • 43. Adami, Hans-Olov
    et al.
    Bergström, Reinhold
    Uppsala University, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Faculty of Social Sciences, Department of Information Science.
    Weiderpass, Elisabete
    Persson, Ingemar
    Barlow, Lotti
    McLaughlin, Joseph K.
    Risk for endometrial cancer following breast cancer: A prospective study in Sweden1997In: Cancer Causes & Control, Vol. 8, p. 821-827Article in journal (Refereed)
  • 44. Adami, H-O
    et al.
    Bergström, R
    Uppsala University, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Faculty of Social Sciences, Department of Information Science.
    Engholm, G
    Nyrén, O
    Wolk, A
    Ekbom, A
    Englund, A
    Baron, J
    A prospective study of smoking and risk of prostate cancer1996In: Int J Cancer, Vol. 67, p. 764-768Article in journal (Refereed)
  • 45.
    Adami, J
    et al.
    Uppsala University, Humanistisk-samhällsvetenskapliga vetenskapsområdet, Faculty of Social Sciences, Department of Information Science.
    Nyren, O
    Bergstrom, R
    Ekbom, A
    McLaughlin, JK
    Hogman, C
    Fraumeni, JF
    Glimelius, B
    Blood transfusion and non-Hodgkin lymphoma: Lack of association1997In: ANNALS OF INTERNAL MEDICINE, ISSN 0003-4819, Vol. 127, no 5, p. 365-&Article in journal (Refereed)
  • 46. Addario-Berry, Louigi
    et al.
    Broutin, Nicolas
    Holmgren, Cecilia
    Stockholms universitet, Matematiska institutionen.
    Cutting down trees with a Markov chainsaw2014In: The Annals of Applied Probability, ISSN 1050-5164, E-ISSN 2168-8737, Vol. 24, no 6, p. 2297-2339Article in journal (Refereed)
    Abstract [en]

    We provide simplified proofs for the asymptotic distribution of the number of cuts required to cut down a Galton-Watson tree with critical, finite-variance offspring distribution, conditioned to have total progeny n. Our proof is based on a coupling which yields a precise, nonasymptotic distributional result for the case of uniformly random rooted labeled trees (or, equivalently, Poisson Galton-Watson trees conditioned on their size). Our approach also provides a new, random reversible transformation between Brownian excursion and Brownian bridge.

  • 47. Addario-Berry, Louigi
    et al.
    Janson, Svante
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    McDiarmid, Colin
    On the Spread of Random Graphs2014In: Combinatorics, probability & computing, ISSN 0963-5483, E-ISSN 1469-2163, Vol. 23, no 4, p. 477-504Article in journal (Refereed)
    Abstract [en]

    The spread of a connected graph G was introduced by Alon, Boppana and Spencer [1], and measures how tightly connected the graph is. It is defined as the maximum over all Lipschitz functions f on V(G) of the variance of f(X) when X is uniformly distributed on V(G). We investigate the spread for certain models of sparse random graph, in particular for random regular graphs G(n,d), for Erdos-Renyi random graphs G(n,p) in the supercritical range p > 1/n, and for a `small world' model. For supercritical G(n,p), we show that if p = c/n with c > 1 fixed, then with high probability the spread of the giant component is bounded, and we prove corresponding statements for other models of random graphs, including a model with random edge lengths. We also give lower bounds on the spread for the barely supercritical case when p = (1 + o(1))/n. Further, we show that for d large, with high probability the spread of G(n, d) becomes arbitrarily close to that of the complete graph K-n.

  • 48. Adimurthi,
    et al.
    Marcos do O, Joao
    Tintarev, Kyril
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Analysis and Applied Mathematics.
    Cocompactness and minimizers for inequalities of Hardy-Sobolev type involving N-Laplacian2010In: NoDEA. Nonlinear differential equations and applications (Printed ed.), ISSN 1021-9722, E-ISSN 1420-9004, Vol. 17, no 4, p. 467-477Article in journal (Refereed)
    Abstract [en]

    The paper studies quasilinear elliptic problems in the Sobolev spaces W-1,W-p(Omega), Omega subset of R-N, with p = N, that is, the case of Pohozhaev-Trudinger-Moser inequality. Similarly to the case p < N where the loss of compactness in W-1,W-p(R-N) occurs due to dilation operators u bar right arrow t((N-p)/p)u(tx), t > 0, and can be accounted for in decompositions of the type of Struwe's "global compactness" and its later refinements, this paper presents a previously unknown group of isometric operators that leads to loss of compactness in W-0(1,N) over a ball in R-N. We give a one-parameter scale of Hardy-Sobolev functionals, a "p = N"-counterpart of the Holder interpolation scale, for p > N, between the Hardy functional integral vertical bar u vertical bar(p)/vertical bar x vertical bar(p) dx and the Sobolev functional integral vertical bar u vertical bar(pN/(N-mp)) dx. Like in the case p < N, these functionals are invariant with respect to the dilation operators above, and the respective concentration-compactness argument yields existence of minimizers for W-1,W-N-norms under Hardy-Sobolev constraints.

  • 49.
    Adimurthi,
    et al.
    TIFR CAM, PB 6503, Bangalore 560065, Karnataka, India.
    Tintarev, Kyril
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Analysis and Probability Theory.
    Defect of compactness in spaces of bounded variation2016In: Journal of Functional Analysis, ISSN 0022-1236, E-ISSN 1096-0783, Vol. 271, no 1, p. 37-48Article in journal (Refereed)
    Abstract [en]

    Defect of compactness for non-compact imbeddings of Banach spaces can be expressed in the form of a profile decomposition. Let X be a Banach space continuously imbedded into a Banach space Y, and let D be a group of linear isometric operators on X. A profile decomposition in X, relative to D and Y, for a bounded sequence (x(k))(k is an element of N) subset of X is a sequence (S-k)(k is an element of N), such that (x(k) - S-k)(k is an element of N) is a convergent sequence in Y, and, furthermore, S-k has the particular form S-k = Sigma(n is an element of N)g(k)((n))W((n)) with g(k)((n)) is an element of D and w((n)) is an element of X. This paper extends the profile decomposition proved by Solimini [10] for Sobolev spaces (H) over dot(1,P)(R-N) with 1 < p < N to the non-reflexive case p = 1. Since existence of "concentration profiles" w((n)) relies on weak-star compactness, and the space (H) over dot(1,1) is not a conjugate of a Banach space, we prove a corresponding result for a larger space of functions of bounded variation. The result extends also to spaces of bounded variation on Lie groups.

  • 50. Adimurthi,
    et al.
    Tintarev, Kyril
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics, Analysis and Applied Mathematics.
    Hardy inequalities for weighted Dirac operator2010In: Annali di Matematica Pura ed Applicata, ISSN 0373-3114, E-ISSN 1618-1891, Vol. 189, no 2, p. 241-251Article in journal (Refereed)
    Abstract [en]

    An inequality of Hardy type is established for quadratic forms involving Dirac operator and a weight r(-b) for functions in R-n. The exact Hardy constant c(b) = c(b) (n) is found and generalized minimizers are given. The constant cb vanishes on a countable set of b, which extends the known case n = 2, b = 0 which corresponds to the trivial Hardy inequality in R-2. Analogous inequalities are proved in the case c(b) = 0 under constraints and, with error terms, for a bounded domain.

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