JOINT ICTP/SISSA STATISTICAL PHYSICS SEMINAR:"Form factors in finite volume and finite temperature correlators"
Starts 20 Jan 2009 12:30
Ends 20 Jan 2009 20:00
Central European Time
Lecture Room D-SISSA Main Building
I review recent work related to the volume dependence of matrix elements of local fields (form factors), giving a description valid to all orders in inverse powers of the volume (i.e. only neglecting contributions that decay exponentially with volume). This method can be used to test exact solutions (derived using bootstrap methods in integrable models) against numerical data obtained by solving the field theory in a truncated state space; it is also useful in extracting matrix elements from numerical data such as those obtained from e.g. lattice field theory. Matrix elements with disconnected pieces require special attention. Such matrix elements are important in computing finite temperature correlation functions. I give a new method for generating a low temperature expansion, which is evaluated for the one-point function up to third order, confirming a series expansion conjectured by Leclair and Mussardo. Time permitting, I also briefly show how the results can be extended to a situation with boundaries.