Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics.

Preti, Michelangelo

KTH Royal Inst Technol, NORDITA, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden;Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden.

2019 (English)In: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 798, article id 134971Article in journal (Refereed) Published

Abstract [en]

We introduce bi-fermion fishnet theories, a class of models describing integrable sectors of four-dimensional gauge theories with non-maximal supersymmetry. Bi-fermion theories are characterized by a single complex scalar field and two Weyl fermions interacting only via chiral Yukawa couplings. The latter generate oriented Feynman diagrams forming hexagonal lattices, whose fishnet structure signals an underlying integrability that we exploit to compute anomalous dimensions of BMN-vacuum operators. Furthermore, we investigate Lunin-Maldacena deformations of N = 2 superconformal field theories with deformation parameter gamma and prove that bi-fermion models emerge in the limit of large imaginary gamma and vanishing 't Hooft coupling g, with ge(-i/2 gamma) fixed. Finally, we explicitly find non-trivial conformal fixed points and compute the scaling dimensions of operators for any gamma and in presence of double-trace deformations.

Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics.

2018 (English)In: Nuclear Physics B, ISSN 0550-3213, E-ISSN 1873-1562, Vol. 935, p. 271-289Article in journal (Refereed) Published

Abstract [en]

We find the Yangian symmetry underlying the integrability of type IIB superstrings on AdS(3) x S-3 x S-3 x S-1 with mixed Ramond-Ramond and Neveu-Schwarz-Neveu-Schwarz flux. The abstract commutation relations of the Yangian are formulated via RTT realisation, while its matrix realisation is in an evaluation representation depending on the quantised coefficient of the Wess-Zumino term. The construction naturally encodes a secret symmetry of the worldsheet scattering matrix whose generators map different Yangian levels to each other. We show that in the large effective string tension limit the Yangian becomes a deformation of a unitary loop algebra and we derive its universal classical r-matrix.