Maths HEP Lunchtime Seminars: On general properties of boundary renormalization goup flows in two dimensions
23 February 2007 13:00 in CM221
I will discuss one-dimensional quantum systems with boundary which are
critical in the bulk but not critical at the boundary.
Renormalization goup (RG) generates a flow on the space of boundary
conditions in such systems.
Following Affleck and Ludwig one can define a quantity called "boundary
entropy" which can be shown to monotonically decrease along the
boundary renormalization flows. For supersymmetric systems in addition
one can prove that the free energy of the system monotonically
decreases as well. I will discuss how these statements can be proved
and what can be said about lower bounds on the boundary entropy.