Nonperturbative effects in equilibrium finite-temperature scalar field theory

We investigate the two-loop gap equation for the thermal mass of hot massless g2ϕ4 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 g2 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 g4 order in perturbation theory.

Download Full-text

Mass singularities at finite temperature in a scalar field theory

Zeitschrift für Physik C Particles and Fields ◽

10.1007/bf01550935 ◽

1989 ◽

Vol 43 (4) ◽

pp. 575-580 ◽

Cited By ~ 22

Author(s):

T. Grandou ◽

M. Bellac ◽

J. -L. Meunier

Keyword(s):

Field Theory ◽

Scalar Field ◽

Finite Temperature ◽

Scalar Field Theory

Download Full-text

BLOCH–NORDSIECK ESTIMATES OF A HIGH-TEMPERATURE SCALAR FIELD THEORY

International Journal of Modern Physics A ◽

10.1142/s0217751x05028417 ◽

2005 ◽

Vol 20 (32) ◽

pp. 7525-7546 ◽

Cited By ~ 3

Author(s):

B. CANDELPERGHER ◽

H. M. FRIED ◽

T. GRANDOU

Keyword(s):

Field Theory ◽

High Temperature ◽

Scalar Field ◽

Heat Bath ◽

Damping Factor ◽

Scalar Field Theory ◽

Clear Cut ◽

Subsequent Application ◽

Thermal Medium ◽

Temperature Scalar

In anticipation of subsequent application to QED and QCD, we consider the case of a model, high temperature, relativistic, scalar field theory. We introduce into the exact, nonperturbative, functional expressions of this "quenched" model, a new Fradkin representation, and extract the infrared/Bloch–Nordsieck/(IR/BN) contributions of every perturbative graph, in order to circumvent the lack of a clear-cut separation of energy scales of previous semiperturbative treatments. Our results are applicable to the absorption of a fast particle which enters a heat bath, as well as to the propagation of a symmetric pulse within the thermal medium due to the appearance of an instantaneous, shockwave-like source acting in the medium. In momentum space, the former case displays a propagator which decays exponentially with increasing time, in addition to a new damping factor independent of time. The latter case displays an exponential growth with time of the symmetric pulse, generating effective and increasing plasmon waves, in competition with damping independent of time. When extended to QCD, qualitative applications could be made to RHIC scattering, in which a fireball appears, expands and is damped away.

Download Full-text

THERMAL RENORMALONS IN SCALAR FIELD THEORY

Modern Physics Letters A ◽

10.1142/s0217732300001481 ◽

2000 ◽

Vol 15 (18) ◽

pp. 1181-1190 ◽

Cited By ~ 7

Author(s):

M. LOEWE ◽

C. VALENZUELA

Keyword(s):

Field Theory ◽

Scalar Field ◽

Temperature Dependence ◽

Finite Temperature ◽

Temperature Dependent ◽

Scalar Theory ◽

Scalar Field Theory

In the framework of the scalar theory gϕ4, we explore the occurrence of thermal renormalons, i.e. temperature-dependent singularities in the Borel plane. The discussion of a particular renormalon type diagram at finite temperature, using Thermofield Dynamics, allows us to establish that these singularities actually get a temperature dependence. This dependence appears in the residues of the poles, the positions of the poles remain unchanged with temperature.

Download Full-text