Found 13 result(s)

15.11.2017 (Wednesday)

Polygon Seminar: Dualities in d=2+1 Dimensions

Triangular Seminar David Tong (DAMTP)

at:
15:00 QMW
room GO Jones Lecture Theatre
abstract:

I'll give a basic introduction to particle-vortex duality in d=2+1 dimensions and its relation to 3d bosonization.

14.10.2015 (Wednesday)

The Supersymmetric Quantum Hall Effect

Regular Seminar David Tong (DAMTP, Cambridge)

at:
13:15 KCL
room S0.13
abstract:

There exist, in d=2+1 dimensions, field theories that are supersymmetric but non-relativistic. I will show that the low-energy physics of these theories is that of the fractional quantum Hall effect. Supersymmetry provides enough analytic control to explicitly derive the ground state wavefunctions and their excitations.

28.01.2015 (Wednesday)

Euclidean Quantum Supergravity

Regular Seminar David Tong (Cambridge)

at:
14:00 IC
room H503
abstract:

I'll revisit some old of ideas of Euclidean quantum gravity, in which manifolds of different topology are summed in the path integral. I'll show that, in certain circumstances, gravitational instantons can destabilise supersymmetric Kaluza-Klein compactifications. We'll also see how one-loop divergences in quantum gravity can be subsumed into a new RG-invariant topological scale.

17.10.2013 (Thursday)

Holographic Conductivity

Regular Seminar David Tong (Cambridge)

at:
14:00 QMW
room Room 208
abstract:

I'll review some progress over the past 18 months in computing Ohm's law using holography.

29.01.2013 (Tuesday)

Uses of String Theory

Regular Seminar David Tong (DAMTP, Cambridge)

at:
16:00 City U.
room CG04
abstract:

24.02.2010 (Wednesday)

Inching Towards Strange Metallic Holography

Regular Seminar David Tong (DAMTP, Cambridge)

at:
14:00 IC
room H503
abstract:

Strange metals are materials with numerous anomalous properties. The flow of electricity cannot be explained in the familiar language of a fluid of individual electrons, but instead requires a new strongly interacting description. In this talk, I will review some basic facts about these materials. With this as motivation, I will explain how to compute conductivity in certain strongly interacting, non-relativistic field theories which are defined holographically.

22.01.2009 (Thursday)

Berry Phase and Supersymmetry

Regular Seminar David Tong (DAMTP, Cambridge)

at:
13:45 QMW
room 208
abstract:

21.11.2008 (Friday)

London Mathematical Society Graduate Student Meeting

Exceptional Seminar Neil Lambert. David Tong. ()

at:
09:00 KCL
room 1.71 of Franklin-Wilkins Building
abstract:

Neil Lambert (KCL) 'From D-branes to M-branes', David Tong (DAMTP) 'Quantum vortex strings' plus several presentations by PhD students on their work. Ends at 14:15. See www.mth.kcl.ac.uk/'tilde'anderl/LMSpremeeting/

03.11.2008 (Monday)

Holonomy, Berry Phase, and Supersymmetry

String Theory & Geometry Seminar David Tong (Cambridge)

at:
13:00 IC
room IMS seminar room
abstract:

As parameters in quantum mechanics are slowly varied, states undergo a non-Abelian holonomy known as Berry phase. I will review the ideas behind the Berry phase and explain how supersymmetry imposes restrictions on the holonomy. The associated non-Abelian gauge connections must obey certain first order equations which are related to the self-dual Yang-Mills equations, specifically the Hitchin equations, tt star equations, and Bogomolnyi equations. I will end by showing how one can build a BPS 't Hooft-Polyakov monopole in the lab.

07.11.2007 (Wednesday)

Berry's Phase, Supersymmetry and D-Branes

Regular Seminar David Tong (DAMTP)

at:
13:15 KCL
room 423
abstract:

Berry's phase is a beautiful and simple idea in quantum mechanics, with application to many areas of condensed matter physics. After reviewing the non-Abelian version of Berry's phase, I will explain how this concept naturally fits together with supersymmetry. I will then show how to compute Berry's phase in D-brane systems, using both traditional quantum mechanics, as well as AdS/CFT techniques.

22.03.2006 (Wednesday)

D-branes in Field Theory

Regular Seminar David Tong (Cambridge)

at:
13:15 KCL
room 423
abstract:

09.02.2005 (Wednesday)

Splitting the Conifold Singularity

Triangular Seminar David Tong (Cambridge)

at:
15:00 KCL
room 3B20
abstract:

This talk is part of the joint Triangular Seminars.

14.10.2004 (Thursday)

Vortices, Strings and Vortex Strings

Regular Seminar David Tong (Cambridge)

at:
16:30 IC
room H503
abstract:

I will summarise recent progress in understanding the dynamics of vortices in gauge theories and describe how the vortices can be used as probes to extract information about the strong coupling quantum dynamics of the theory in which its embedded.