# Mathematical Physics Seminar

Speaker:
Marc Herrmann
Topic:
The Vacuum in Light-Front Field Theory

Abstract:
By using the light-front formulation of quantum field theory, one can construct a relatively simple relationship between the vacuum of an interacting theory and the vacuum of a free theory. In the usual formulation, this relationship becomes problematic as a result of incorporating the infinite number of canonical variables required for a field theory. We’ll discuss a simple model, based on the coherent states of a harmonic oscillator, which clarifies how the light-front formulation can get around these difficulties.
To further explain the unusual behavior of the light-front vacuum, we can use the techniques of algebraic quantum field theory. In this setup, the theory is constructed from just two ingredients, a $C^*$-algebra constructed from the possible observables of the theory, and positive linear functional corresponding to the vacuum vector.

Event Date:
September 24, 2019 - 2:30pm to 3:20pm
Location:
309 VAN
Calendar Category:
Seminar
Seminar Category:
Mathematical Physics