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Speakers: Blaise Gouteraux (Ecole Polytechnique, Paris) and Fridrik Freyr Gautason (KU Leuven). Location: Utrecht, Unnik building 220.

Event details of Holography: triangle meeting
Date 30 November 2018
Time 13:00 -18:00
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Programme 

13:30 Tea & Coffee

14:00 Blaise Gauteroux (Ecole Polytechnique, Paris)Slow relaxation and diffusion in holography 

15:15 Coffee break

15:45 Fridrik Freyr Gautason (KU Leuven)The three twists of N = 4 and holography

17:00 Borrel (drinks and snacks) The Basket, Genevelaan 8, 3584 CC Utrecht (next to Unnik-building)

Abstracts

Blaise Gauteroux (Ecole Polytechnique, Paris)Slow relaxation and diffusion in holography 

Abstract: The dissipative dynamics of strongly interacting systems are often characterised by the timescale set by the inverse temperature $\tau_P\sim\hbar/(k_BT)$. So are the dynamics near black hole horizons. I will explain how this statement needs to be amended in the presence of weakly broken symmetries, and/or near quantum critical points in the presence of a dangerously irrelevant deformation. In both cases, there is a collective excitation (a quasinormal mode of the dual black hole spacetime) whose lifetime $\tau_{eq}$ is parametrically longer than $\tau_P$: $\tau_{eq}\gg T^{-1}$. This generally leads to anomalously large diffusivities (in units of the butterfly velocity), governed by $\tau_{eq}$ rather than $\tau_P$. The existence of this long-lived excitation also means that the system equilibrates slowly on timescales much longer than $\tau_P$. 

Fridrik Freyr Gautason (KU Leuven)The three twists of N = 4 and holography 

Abstract: I will start by reviewing the three inequivalent topological twists of N = 4 SYM on arbitrary four-manifolds and briefly discuss the resulting topological QFTs. I will emphasise the role played by global anomalies of N = 4 in our story and the relation to anomalies in the TQFTs. I will then construct type IIB supergravity solutions that are holographic duals to the aforementioned twists.

Location

Willem C. van Unnikgebouw ('Unnik'), room 220, Heidelberglaan 2, Utrecht >>GoogleMaps

Local organiser

Umut Gursoy (UU)

About

This event is part of a regular series of meetings sponsored by Delta ITP with the objective of bringing together the theoretical physics communities in Amsterdam, Leiden, Utrecht and our sister nodes Groningen, Brussels (ULB and VUB) and Leuven. The topic of this meeting is holography and its applications to different physical systems. We encourage researchers from different areas in theoretical physics to participate!