Gap Equation in Scalar Field Theory at Finite Temperature
Abstract
We investigate the twoloop gap equation for the thermal mass of hot massless g^{2}ϕ^{4} theory and find that the gap equation itself has a nonzero finite imaginary part. This implies that it is not possible to find the real thermal mass as a solution of the gap equation beyond g^{2} order in perturbation theory. We have solved the gap equation and obtained the real and imaginary parts of the thermal mass which are correct up to g^{4} order in perturbation theory.
 Publication:

Modern Physics Letters A
 Pub Date:
 1999
 DOI:
 10.1142/S0217732399000304
 arXiv:
 arXiv:hepth/9705177
 Bibcode:
 1999MPLA...14..257M
 Keywords:

 High Energy Physics  Theory
 EPrint:
 13 pages, Latex with axodraw, Minor corrections, Appendix added