A series of four lectures exploring the Exact Renormalization Group. This non-credit mini course will be offered at Perimeter Institute between April 16 and May 7 2008. http://pirsa.org/podcast/C08006 Science 2012 http://blogs.law.harvard.edu/tech/rss en-ca Thu, 09 Feb 2012 04:34:42 -0500 sbradwell@perimeterinstitute.ca Thu, 09 Feb 2012 04:34:42 -0500 G 180 pirsa-admin@perimeterinstitute.ca Steve Bradwell's - Podcast Generator 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. Oliver Rosten http://streamer.perimeterinstitute.ca/mp3/44d656cf-ceac-4509-a281-eb21c7510378.mp3 Science http://streamer.perimeterinstitute.ca/mp3/44d656cf-ceac-4509-a281-eb21c7510378.mp3 Wed, 16 Apr 2008 10:30:00 -0400 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. Oliver Rosten http://streamer.perimeterinstitute.ca/mp3/1aec186b-424c-4944-9400-a2424e19f47d.mp3 Science http://streamer.perimeterinstitute.ca/mp3/1aec186b-424c-4944-9400-a2424e19f47d.mp3 Wed, 23 Apr 2008 10:30:00 -0400 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. Oliver Rosten http://streamer.perimeterinstitute.ca/mp3/b2628b1d-f16c-4f6e-8b7a-260b4ad36601.mp3 Science http://streamer.perimeterinstitute.ca/mp3/b2628b1d-f16c-4f6e-8b7a-260b4ad36601.mp3 Wed, 30 Apr 2008 10:30:00 -0400 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 gauge invariant ERGs. I will discuss the formulation, what has been achieved to date, and what can reasonably be hoped for in the future. Oliver Rosten http://streamer.perimeterinstitute.ca/mp3/17b7323b-8534-4973-a075-205e7992af7e.mp3 Science http://streamer.perimeterinstitute.ca/mp3/17b7323b-8534-4973-a075-205e7992af7e.mp3 Wed, 07 May 2008 10:30:00 -0400