PhD Thesis: Non-conformal gauge/string duality. A rigorous case study

Thesis defense

Monday 04 September 2017
from 13:30
to 15:00 at
FB42

Speaker :

Xinyi Chen-Lin (Nordita and Uppsala University)

Abstract :

The gauge/string duality, a.k.a. the holographic principle is a profound assertion that emerged
from string theory. It relates strongly-coupled gauge theories to weakly coupled string theories
living in a higher-dimensional curved geometry. Nevertheless, it is a conjecture, and only a few
instances of its more concrete form, the AdS/CFT correspondence, are well-understood. The
most well-studied example is the duality between N=4 SYM, which is a CFT, and type IIB string
theory in AdS5xS5 background. Generalization to less symmetric cases is a must, and the next
logical step is to add a mass scale to N=4 SYM, therefore breaking its conformal symmetry and
leading to N=2* SYM, the theory we study in this thesis. It is supersymmetric enough to employ
the powerful localization method that reduces its partition function to a matrix model. We will
see that the mass scale causes non-trivial phase structures in its vacuum configuration, visible
in the holographic regime. We will probe them using Wilson loops in different representations
of the gauge group. On the other hand, the dual supergravity background was derived by Pilch-Warner, making N=2* theory an explicitly testable non-conformal holographic case, which is
a rare example. We will prove that the duality works for the dual observables (string action,
D-branes) we managed to compute, even at a quantum-level.