scholarly journals Degenerate fermion and Wilson loops in 1 + 1 dimensions

1990 ◽  
Vol 68 (4-5) ◽  
pp. 357-360
Author(s):  
Kiyoshi Shiraishi
Keyword(s):  
Phase Transition ◽  
Boundary Condition ◽  
Symmetry Breaking ◽  
Finite Temperature ◽  
Fermion Field ◽  
Wilson Loops ◽  
Finite Density ◽  
Gauge Symmetries ◽  
Antiperiodic Boundary Condition

We investigate the effect of finite fermion density on symmetry breaking by Wilson loops in (1 + 1) dimensions. We find the breaking and restoration of symmetry at finite density in models with SU(2) and SU(3) gauge symmetries, in the presence of the adjoint fermions. The transition can occur at a finite density of fermions, regardless of the periodic or antiperiodic boundary condition of the fermion field; this is in contrast to the finite-temperature case examined by Ho and Hosotani (IASSNS-HEP preprint 88/48) where the boundary condition of fractional twist is essential to the occurrence of the phase transition.

SYMMETRY BREAKING BY WILSON LINES AND FINITE TEMPERATURE AND DENSITY EFFECTS

1993 ◽  
Vol 08 (16) ◽  
pp. 1495-1505 ◽  
Author(s):  
CHUNG-CHIEH LEE ◽  
CHOON-LIN HO
Keyword(s):  
Boundary Condition ◽  
Symmetry Breaking ◽  
Detailed Analysis ◽  
Gauge Group ◽  
Finite Temperature ◽  
Wilson Line ◽  
Adjoint Representation ◽  
Critical Temperatures ◽  
Massless Fermion ◽  
Breaking Mechanism

Effects of both finite temperature and density on Wilson line symmetry breaking mechanism is considered for an SU(N) theory defined on space-time manifold R1,d−2×S1 with massless fermion in the adjoint representation of the gauge group. Detailed analysis is given for the groups SU(2) and SU(3) on R1,2×S1. It is found that, at fixed fermion boundary condition, the critical temperatures and densities at which the full SU(N) symmetry is restored are the same for N=2 and N=3.

Symmetry breaking by Wilson loops. Finite-temperature effects

1989 ◽  
Vol 39 (8) ◽  
pp. 2368-2372 ◽  
Author(s):  
J. S. Dowker ◽  
S. P. Jadhav
Keyword(s):  
Symmetry Breaking ◽  
Finite Temperature ◽  
Temperature Effects ◽  
Wilson Loops

scholarly journals Symmetry Restoration and Breaking at Finite Temperature: An Introductory Review

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 733 ◽  
Author(s):  
Eibun Senaha
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Symmetry Breaking ◽  
Finite Temperature ◽  
Electroweak Symmetry ◽  
Electroweak Phase Transition ◽  
First Order ◽  
Hot Environment ◽  
First Order Phase Transition ◽  
First Order Phase

Symmetries at finite temperature are of great importance to understand dynamics of spontaneous symmetry breaking phenomena, especially phase transitions in early Universe. Some symmetries such as the electroweak symmetry can be restored in hot environment. However, it is a nontrivial question that the phase transition occurs via first or second order, or even smooth crossover, which strongly depends on underlying physics. If it is first order, gravitational waves can be generated, providing a detectable signal of this epoch. Moreover, the baryon asymmetry of the Universe can also arise under some conditions. In this article, the electroweak phase transition is reviewed, focusing particularly on the case of the first-order phase transition. Much attention is paid to multi-step phase transitions in which additional symmetry breaking such as a spontaneous Z 2 breaking plays a pivotal role in broadening the possibility of the first-order electroweak phase transition. On the technical side, we review thermal resummation that mitigates a bad infrared behavior related to the symmetry restoration. In addition, gauge and scheme dependences of perturbative calculations are also briefly discussed.

Ring-diagram summations in the finite-temperature effective potential

1993 ◽  
Vol 71 (5-6) ◽  
pp. 227-236 ◽  
Author(s):  
M. E. Carrington
Keyword(s):  
Phase Transition ◽  
Standard Model ◽  
Effective Potential ◽  
Finite Temperature ◽  
Electroweak Phase Transition ◽  
First Order ◽  
Ring Diagram ◽  
First Order Phase Transition ◽  
The Standard Model ◽  
The One

There has been much recent interest in the finite-temperature effective potential of the standard model in the context of the electroweak phase transition. We review the calculation of the effective potential with particular emphasis on the validity of the expansions that are used. The presence of a term that is cubic in the Higgs condensate in the one-loop effective potential appears to indicate a first-order electroweak phase transition. However, in the high-temperature regime, the infrared singularities inherent in massless models produce cubic terms that are of the same order in the coupling. In this paper, we discuss the inclusion of an infinite set of these terms via the ring-diagram summation, and show that the standard model has a first-order phase transition in the weak coupling expansion.

A NUCLEAR MANY-BODY THEORY AT FINITE TEMPERATURE APPLIED TO A PROTONEUTRON STAR

2002 ◽  
Vol 11 (02) ◽  
pp. 83-104 ◽  
Author(s):  
GUILHERME F. MARRANGHELLO ◽  
CESAR A. Z. VASCONCELLOS ◽  
MANFRED DILLIG ◽  
J. A. DE FREITAS PACHECO
Keyword(s):  
Phase Transition ◽  
Nuclear Matter ◽  
Finite Temperature ◽  
Degrees Of Freedom ◽  
Many Body ◽  
Many Body Theory ◽  
The Masses ◽  
Protoneutron Stars ◽  
Protoneutron Star

Thermodynamical properties of nuclear matter are studied in the framework of an effective many-body field theory at finite temperature, considering the Sommerfeld approximation. We perform the calculations by using the nonlinear Boguta and Bodmer model, extended by the inclusion of the fundamental baryon octet and leptonic degrees of freedom. Trapped neutrinos are also included in order to describe protoneutron star properties through the integration of the Tolman–Oppenheimer–Volkoff equations, from which we obtain, beyond the standard relations for the masses and radii of protoneutron stars as functions of the central density, new results of these quantities as functions of temperature. Our predictions include: the determination of an absolute value for the limiting mass of protoneutron stars; new structural aspects on the nuclear matter phase transition via the behavior of the specific heat and, through the inclusion of quark degrees of freedom, the properties of a hadron-quark phase transition and hybrid protoneutron stars

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