The scattering length at positive temperature
arXiv:1111.1683 · doi:10.1007/s11005-012-0566-5
Abstract
A positive temperature analogue of the scattering length of a potential $V$ can be defined via integrating the difference of the heat kernels of $-Î$ and $-Î+ \frac 12 V$, with $Î$ the Laplacian. An upper bound on this quantity is a crucial input in the derivation of a bound on the critical temperature of a dilute Bose gas \cite{SU}. In \cite{SU} a bound was given in the case of finite range potentials and sufficiently low temperature. In this paper, we improve the bound and extend it to potentials of infinite range.
LaTeX, 6 pages