Found 8 result(s)

31.05.2023 (Wednesday)

Triangle Seminar - Entanglement and Emergent Space from Large Matrices

Triangular Seminar Sean Hartnoll (University of Cambridge)

at:
15:00 IC
room Lecture Theatre 2, B113
abstract:

The locality in space of interactions between elementary particles is a key property of our universe. This locality is hardwired into quantum field theoretic descriptions of nature. However, locality and indeed space itself are likely not fundamental concepts. In holographic duality, local interactions on a dynamical spacetime emerge from "large N" matrices where no locality need be manifest in the microscopic Hamiltonian. The emergence of locality from matrix theories is well-established but not well-understood. In recent years it has been appreciated that locally is closely tied up with so-called "area law" entanglement of the microscopic degrees of freedom. I will discuss a particularly robust notion of entanglement in matrix theories that is rooted in an underlying Gauss law constraint and show how simple models of matrix, or 'fuzzy' geometry contain area law entanglement.

28.04.2022 (Thursday)

Entanglement in the quantum Hall matrix model

Regular Seminar Sean Hartnoll (Cambridge)

at:
14:00 QMUL
room G.O.Jones 610
abstract:

Quantum mechanical theories describing large N by N matrices of oscillators can lead to an emergent space as N -> infinity. In the most fully fledged version, the emergent space is dynamical and gravitating. However, there are also simpler, lower dimensional versions of this phenomenon. One of the simplest occurs in the so-called quantum Hall matrix model, in which a 2 dimensional space emerges and supports Chern-Simons dynamics. I will describe how this solvable model leads to insights about the emergence of space from matrices. In particular, I will describe how the emergent spatial locality is reflected in the entanglement structure of the ground state of theory.

22.03.2022 (Tuesday)

The classical interior of black holes in holography

Regular Seminar Sean Hartnoll (University of Cambridge)

at:
14:00 QMUL
room Maths MB-503 and zoom
abstract:

(Email m.godazgar@qmul.ac.uk for zoom link) Abstract: The exterior dynamics of black holes has played a major role in holographic duality, describing the approach to thermal equilibrium of strongly coupled media. The interior dynamics of black holes in a holographic setting has, in contrast, been largely unexplored. I will describe recent work investigating the classical interior dynamics of various holographic black holes. I will discuss the nature of the singularity, the absence of Cauchy horizons and a new kind of chaotic behavior that emerges in the presence of charged scalar fields.

16.03.2022 (Wednesday)

Entanglement in the quantum Hall matrix model

Regular Seminar Sean Hartnoll (Cambridge Univ. DAMTP)

at:
13:45 KCL
room K0.20
abstract:

Quantum mechanical theories describing large N by N matrices of oscillators can lead to an emergent space as N -> infinity. In the most fully fledged version, the emergent space is dynamical and gravitating. However, there are also simpler, lower dimensional versions of this phenomenon. One of the simplest occurs in the so-called quantum Hall matrix model, in which a 2 dimensional space emerges and supports Chern-Simons dynamics. I will describe how this solvable model leads to insights about the emergence of space from matrices. In particular, I will describe how the emergent spatial locality is reflected in the entanglement structure of the ground state of theory.

29.06.2021 (Tuesday)

The classical interior of black holes in holography

Regular Seminar Sean Hartnoll (ITP Stanford University)

at:
13:30 IC
room zoom 871 9223 5980
abstract:

The exterior dynamics of black holes has played a major role in holographic duality, describing the approach to thermal equilibrium of strongly coupled media. The interior dynamics of black holes in a holographic setting has, in contrast, been largely unexplored. I will describe recent work investigating the classical interior dynamics of various holographic black holes. I will discuss the nature of the singularity, the absence of Cauchy horizons and a new kind of chaotic behavior that emerges in the presence of charged scalar fields. [please email a.held@imperial.ac.uk for zoom link or password]

30.11.2005 (Wednesday)

What is the phase structure of N=4 SYM theory?

Regular Seminar Sean Hartnoll (DAMTP)

at:
13:15 KCL
room 423
abstract:

I will review recent results at strong and weak coupling in N=4 SYM theory at finite temperature. I will point out that retarded correlators have a qualitatively different analytic structure in the weak a strong coupling limits and will argue that this either necessitates a phase transition in the theory or requires that we revise our current understanding of weakly coupled plasmas.

24.11.2005 (Thursday)

What is the Phase Structure of N=4 SYM Theory?

Regular Seminar Sean Hartnoll (DAMTP)

at:
14:00 QMW
room 112
abstract:

18.11.2004 (Thursday)

A black hole instability as a phase transition in field theory

Regular Seminar Sean Hartnoll (Cambridge)

at:
16:30 IC
room H503
abstract:

Generalised black holes have a horizon given by an arbitrary Einstein manifold. I will describe a criterion for the classical stability of these black holes. Roughly, spherical horizons are stable but lemon-shaped horizons can be unstable. In Anti-de Sitter space, these black holes are dual to gauge theory on a curved background given by the same Einstein manifold. I will argue that the dual thermal field theory effect is a novel phase transition induced by inhomogeneous Casimir pressures and characterised by a condensation of pressure.