The fascination with string theory centers on its ability to provide a framework in which to think about gravity and quantum mechanics in the same theoretical terms. Its foundation, however, lay in its potential to solve a different long-standing problem: describing the strong force that governs the nucleus of the atom. My research focuses on gauge/gravity dualities in string theory, a development which provides tools to understand both quantum gravity and the strong force.

My principal interest has been the gauge theory applications of gauge/gravity dualities. While quantum chromodynamics (QCD) became the preferred description of the strong force not long after the development of string theory, our ability to study QCD is limited. At the energies typically found inside the nucleus of an atom, QCD is a strongly coupled gauge theory for which we lack the mathematical tools to calculate important physical quantities. Gauge/gravity dualities provide a way to study QCD at these low energies, giving us a more quantitative understanding of confinement, chiral symmetry breaking, and other non-perturbative phenomena.

More recently, I have become interested in possible applications of gauge/gravity duality to condensed matter systems, for example high temperature superconductors. At a quantum critical point, a material undergoes a phase transition driven by fluctuations due to quantum zero point motion rather than due to temperature. For materials where the critical point is strongly interacting and perturbative techniques fail, gauge/gravity duality provides a new method for predicting transport properties in the neighborhood of the the critical point.

For more information see Christopher Herzog's homepage

• S. A. Hartnoll and C. P. Herzog, "Ohm's Law at strong coupling: S duality and the cyclotron resonance", Phys. Rev. D 76, 106012 (2007), [arXiv:0706.3228 [hep-th]].
• C. P. Herzog, A. Karch, P. Kovtun, C. Kozcaz and L. G. Yaffe, "Energy loss of a heavy quark moving through N = 4 supersymmetric Yang-Mills plasma", JHEP 0607, 013 (2006), [arXiv:hep-th/0605158].
• C. P. Herzog and D. T. Son, "Schwinger-Keldysh propagators from AdS/CFT correspondence", JHEP 0303, 046 (2003), [arXiv:hep-th/0212072].