Past Quantum Field Theory Seminar

24 May 2016
12:00
to
13:15
Keith Hannabuss
Abstract

This talk will start with a brief historical review of the classification of solids by their symmetries, and the more recent K-theoretic periodic table of Kitaev. It will then consider some mathematical questions this raises, in particular about the behaviour of electrons on the boundary of materials and in the bulk. Two rather different models will be described, which turn out to be related by T-duality. Relevant ideas from noncommutative geometry will be explained where needed.

  • Quantum Field Theory Seminar
16 February 2016
12:00
to
13:15
Gandalf Lechner
Abstract

In this talk, I will review an inverse scattering construction of interacting integrable quantum field theories on two-dimensional Minkowski space and its ramifications. The construction starts from a given two-body S-matrix instead of a classical Lagrangean, and defines corresponding quantum field theories in a non-perturbative manner in two steps: First certain semi-local fields are constructed explicitly, and then the analysis of the local observable content is carried out with operator-algebraic methods (Tomita-Takesaki modular theory, split subfactor inclusions). I will explain how this construction solves the inverse scattering problem for a large family of interactions, and also discuss perspectives on extensions of this program to higher dimensions and/or non-integrable theories.

  • Quantum Field Theory Seminar
2 February 2016
12:00
to
13:15
Dirk Kreimer (Berlin)
Abstract

Amplitudes in quantum field theory have discontinuities when regarded as
functions of
the scattering kinematics. Such discontinuities can be determined from
Cutkosky rules.
We present a structural analysis of such rules for massive quantum field
theory which combines
algebraic geometry with the combinatorics of Karen Vogtmann's Outer Space.
This is joint work with Spencer Bloch (arXiv:1512.01705).

  • Quantum Field Theory Seminar
1 December 2015
12:00
Ivette Fuentes
Abstract

Hawking radiation and particle creation by an expanding Universe
are paradigmatic predictions of quantum field theory in curved spacetime.
Although the theory is a few decades old, it still awaits experimental
demonstration. At first sight, the effects predicted by the theory are too
small to be measured in the laboratory. Therefore, current experimental
efforts have been directed towards siumlating Hawking radiation and
studying quantum particle creation in analogue spacetimes.
In this talk, I will present a proposal to test directly effects of
quantum field theory in the Earth's spacetime using quantum technologies.
Under certain circumstances, real spacetime distortions (such as
gravitational waves) can produce observable effects in the state of
phonons of a Bose-Einstein condensate. The sensitivity of the phononic
field to the underlying spacetime can also be used to measure spacetime
parameters such as the Schwarzschild radius of the Earth.

  • Quantum Field Theory Seminar

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