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PERIMETER INSTITUTE RECORDED SEMINAR ARCHIVE

Displaying all lectures given by: Oliver Rosten


A New Perspective on Quantum Field Theory
Speaker(s): Oliver Rosten
Abstract: The Exact Renormalization Group (ERG) is a technique which can be fruitfully applied to systems with local interactions that exhibit a large number of degrees of freedom per correlation length. In the first part of the talk I will give a very general overview of the ERG, focussing on its application... read more
Date: 20/10/2010 - 4:00 pm

Triviality from the Exact Renormalization Group
Speaker(s): Oliver Rosten
Abstract: After reviewing Wilson's picture of renormalization, and the associated Exact Renormalization Group, I will show that no (physically acceptable) non-trivial fixed points exist for scalar field theory in D>=4. Consequently, an asymptotic safety scenario is ruled out, and the triviality of the theory ... read more
Date: 30/10/2008 - 2:00 pm

Gauge Theories
Speaker(s): Oliver Rosten
Abstract: At first sight, the ERG does not sit well with gauge theories: a naive implementation of the momentum cutoff central to the ERG breaks gauge invariance. However, things are not as they seem. Not only is it possible to construct a gauge invariant cutoff, but it is possible to construct manifestly gau... read more
Date: 07/05/2008 - 10:30 am

The Derivative Expansion
Speaker(s): Oliver Rosten
Abstract: One of the main strengths of the ERG is that it admits nonperturbative approximation schemes which preserve renormalizability. I will introduce a particularly powerful scheme, the derivative expansion.
Date: 30/04/2008 - 10:30 am

Exact Renormalization Group Equations
Speaker(s): Oliver Rosten
Abstract: I will show how to construct very general ERG equations, and will use this as the starting point for a discussion of Polchinski's equation and its cousins. I will introduce diagrammatics and an associated universal calculus, which will be illustrated with a simple calculation.
Date: 23/04/2008 - 10:30 am

Wilsonian Renormalization
Speaker(s): Oliver Rosten
Abstract: In this lecture, I will discuss Wilson's picture of renormalization and its relation to the Exact Renormalization Group (ERG). In particular, I will focus on how one can understand, in a physically intuitive way, what it is for a quantum field theory to be nonperturbatively renormalizable.
Date: 16/04/2008 - 10:30 am
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