arXiv subjects

E. Antonyan

Publications and source records attributed to E. Antonyan.

5 recordsLinked to original sources

arXiv2009

On 3d N=8 Lorentzian BLG theory as a scaling limit of 3d superconformal N=6 ABJM theory

We elaborate on the suggestion made in arXiv:0806.3498 that the 3d \N=8 superconformal SU(N) Chern-Simons-matter theory of Lorentzian Bagger-Lambert-Gustavson type (L-BLG) can be obtained by a scaling limit (involving sending the level k to infinity and redefining the fields) from the \N=6 superconformal U(N)xU(N) Chern-Simons-matter theory of Aharony, Bergman, Jafferis and Maldacena (ABJM). We show that to implement such a limit in a consistent way one is to extend the ABJM theory by an abelian "ghost" multiplet. The corresponding limit at the 3-algebra level also requires extending the non-antisymmetric Bagger-Lambert 3-algebra underlying the ABJM theory by a negative-norm generator. We draw analogy with similar scaling limits discussed previously for bosonic Chern-Simons theory and comment on some implications of this relation between the ABJM and L-BLG theories.

hep-th↗

arXiv2006

Friction Coefficient for Quarks in Supergravity Duals

We study quarks moving in strongly-coupled plasmas that have supergravity duals. We compute the friction coefficient of strings dual to such quarks for general static supergravity backgrounds near the horizon. Our results also show that a previous conjecture on the bound has to be modified and higher friction coefficients can be achieved.

hep-th↗

arXiv2006

Chiral Symmetry Breaking from Intersecting D-Branes

We study a class of intersecting D-brane models in which fermions localized at different intersections interact via exchange of bulk fields. In some cases these interactions lead to dynamical symmetry breaking and generate a mass for the fermions. We analyze the conditions under which this happens as one varies the dimensions of the branes and of the intersections.

hep-th↗

arXiv2006

The Gross-Neveu Model from String Theory

We study an intersecting D-brane model which at low energies describes (1+1)-dimensional chiral fermions localized at defects on a stack of N_c D4-branes. Fermions at different defects interact via exchange of massless (4+1)-dimensional fields. At weak coupling this interaction gives rise to the Gross-Neveu (GN) model and can be studied using field theoretic techniques. At strong coupling one can describe the system in terms of probe branes propagating in a curved background in string theory. The chiral symmetry is dynamically broken at zero temperature and is restored above a critical temperature T_c which depends on the coupling. The phase transition at T_c is first order at strong coupling and second order at weak coupling.

hep-th↗

arXiv2006

NJL and QCD from String Theory

We study a configuration of D-branes in string theory that is described at low energies by a four-dimensional field theory with a dynamically broken chiral symmetry. In a certain region of the parameter space of the brane configuration the low-energy theory is a non-local generalization of the Nambu-Jona-Lasinio (NJL) model. This vector model is exactly solvable at large N_c and dynamically breaks chiral symmetry at arbitrarily weak 't Hooft coupling. At strong coupling the dynamics is determined by the low-energy theory on D-branes living in the near-horizon geometry of other branes. In a different region of parameter space the brane construction gives rise to large N_c QCD. Thus the D-brane system interpolates between NJL and QCD.

hep-th↗