Dr. Umut Gursoy

My research focuses on strongly coupled quantum field theories and my main interest is to understand the dynamics of these complicated systems by means of String Theory. The idea of "holographic correpondence" that stems from String Theory relates the effective description of QFTs in the strongly interacting regime to Einstein's general relativity. Unlike standard effective field theories, this link - at least in certain cases - provides us with the complete description of the low energy physics, and allows us to calculate the parameters in the effective action. For example, in most cases a quantum field theory at low energies can be effectively described by relativistic hydrodynamics. The theory of hydrodynamics provides the form of the effective action based on the symmetry requirements, however it does not provide the parameters in this action, hence incomplete until these observables are obtained by genuine QFT calculations. This latter task is notoriously complicated for strongly interacting QFTs. This is where the "holographic correspondence" or the "AdS/CFT correspondence" jumps in and provides us these observables by mapping the QFT calculations to semi-classical Gravity, the latter being tractable.

Needless to say, such a surprising link between the greatest two theories of the 20th century, QFT and GR is itself an amazing topic to study, let alone its possible applications. Apart from my interest in the more formal aspects of the correspondence, recently I have been active in applying it to the quantum field theory of the strong interaction, QCD, and various strongly interacting condensed matter systems. Most recentlyI became interested in the magnetically induced phenomena, such as the anomalous transport in quark-gluon and electron-hole plasmas, relevant to quark gluon plasma produced in non-central heavy ion collisions and the recently discovered Weyl semimetals. As an independent line of research I am trying to understand quantum gravity, in particular physics around space-like singularities in lower dimensional theories such as two dimensional non-critical string theories.