David A. Sahakyan

Learn More
Little String Theory (LST) is a still somewhat mysterious theory that describes the dynamics near a certain class of time-like singularities in string theory. In this paper we discuss the topological version of LST, which describes topological strings near these sin-gularities. For 5 + 1 dimensional LSTs with sixteen supercharges, the topological version(More)
The low energy dynamics of a certain D-brane configuration in string theory is described at weak t'Hooft coupling by a nonlocal version of the Nambu-Jona-Lasinio model. We study this system at finite temperature and strong t'Hooft coupling, using the string theory dual. We show that for sufficiently low temperatures chiral symmetry is broken, while for(More)
We study the properties of a D-brane in the presence of k NS5 branes. The Dirac-Born-Infeld action describing the dynamics of this D-brane is very similar to that of a non-BPS D-brane in ten dimensions. As the D-brane approaches the fivebranes, its equation of state approaches that of a pressureless fluid. In non-BPS D-brane case this is considered as an(More)
We consider corrections to the Penrose limit of AdS3×S with NS-NS flux which are due to the terms next to leading order in inverse radius expansion. The worldsheet theory of a lightcone string is interacting due to the presence of quartic terms in the action. Perturbative corrections to the spectrum are shown to agree with the results from the exact(More)
We study the N = 2 string theory or the N = 4 topological string on the deformed CHS background. That is, we consider the N = 2 minimal model coupled to the N = 2 Liouville theory. This model describes holographically the topological sector of Little String Theory. We use degenerate vectors of the respective N = 2 Verma modules to find the set of BRST(More)
It has been shown by Batyrev and Borisov that nef partitions of reflexive polyhedra can be used to construct mirror pairs of complete intersection Calabi–Yau manifolds in toric ambient spaces. We construct a number of such spaces and compute their cohomological data. We also discuss the relation of our results to complete intersections in weighted(More)
O.M. Khudaverdian Laboratory of Computing Technique and Automation, Joint Institute for Nuclear Research Dubna, Moscow Region 141980, Russia, on leave of absence from Department of Theoretical Physics of Yerevan State University, 375049 Yerevan, Armenia e-mails: ”khudian@vxjinr.jinr.ru”, ”khudian@sc2a.unige.ch” D.A. Sahakyan Department of Theoretical(More)