Maths HEP Lunchtime Seminars: One-point functions in finite volume/temperature
24 October 2014 13:00 in CM221
We consider finite volume (or equivalently, finite temperature) expectation values of local operators in integrable quantum field theories using a combination of numerical and analytical approaches. It is shown that the low-temperature expansion proposed by Leclair and Mussardo, and its generalisation to excited states proposed by Pozsgay, that are using thermodynamic Bethe Ansatz and form factor techniques, can be matched with high precision by the truncated conformal space approach, when supplemented with renormalization group. Besides verifying the consistency of the two descriptions, their combination leads to an evaluation of expectation values which is valid to a very high precision for all volume/temperature scales.