Applications of the Gauge/Gravity Duality

This book begins with a pedagogical introduction to how duality can be used to extract transport properties of quantum systems from their gravity dual. It then presents new results on hydrodynamic transport in strongly interacting quantum fluids and provides strong evidence that the Haack-Yarom identity between second-order transport coefficients holds for all fluids with a classical gravity dual and may be a universal feature of all strongly coupled quantum fluids such as the quark-gluon plasma (QGP). Many open questions in theoretical physics pertain to strongly interacting quantum systems such as the quark-gluon plasma (QGP) produced in heavy-ion collisions or the strange-metal phase observed in many high-temperature superconductors. These systems are notoriously difficult to study using traditional methods such as perturbation theory, but the gauge/gravity duality offers a successful alternative approach, which maps strongly interacting quantum gauge theories to computationally tractable, classical gravity theories. Newly derived Kubo formulae, expressing transport coefficients in terms of quantum correlators, hold independently of the duality. Lastly, the book discusses new findings on magnetic impurities in strongly correlated metals, including the first dual gravity description of an inter-impurity coupling, crucial for the quantum criticality underlying the strange metal phase.

Auteur

Jonas Probst studied Physics and Mathematics at the TU Munich, the University of Cambridge, and the École Normale Supérieure Paris. For his PhD in Theoretical Physics at the University of Oxford he conducted research on the Gauge/String Duality. His studies and research were funded by the German National Academic Foundation, the Bavarian Max Weber Programme, and the Clarendon Fund of the University of Oxford. He is now working as a Machine Intelligence Engineer at Merantix, Berlin, researching deep neural networks and their applications to time-series predictions, medical imaging, and autonomous driving.

Résumé

Many open questions in Theoretical Physics pertain to strongly interacting quantum systems such as the quark-gluon plasma (QGP) produced in heavy-ion collisions or the strange-metal phase observed in many high-temperature superconductors. These systems are notoriously difficult to study using traditional methods such as perturbation theory, but the gauge/gravity duality offers a successful alternative approach, which maps strongly interacting quantum gauge theories to computationally tractable, classical gravity theories. This book begins with a pedagogical introduction to how the duality can be used to extract transport properties of quantum systems from their gravity dual. It then presents new results on hydrodynamic transport in strongly interacting quantum fluids, providing strong evidence that the Haack-Yarom identity between second-order transport coefficients holds for all fluids with a classical gravity dual and may be a universal feature of all strongly coupled quantum fluids such as the QGP. Newly derived Kubo formulae, expressing transport coefficients in terms of quantum correlators, hold independently of the duality. Lastly, the book discusses new results on magnetic impurities in strongly correlated metals, including the first dual gravity description of an inter-impurity coupling, crucial for the quantum criticality underlying the strange-metal phase.

Contenu
Introduction.- The Gauge/Gravity Duality.- Correlators and Transport.- Second-Order Hydrodynamics and Universality in Non-Conformal Holographic Fluids.- A Holographic Kondo Model.- Conclusion.