scholarly journals Finite temperature gluon self-energy in a class of temporal gauges

2000 ◽  
Vol 61 (12) ◽  
Author(s):  
F. T. Brandt ◽  
J. Frenkel ◽  
F. R. Machado
Keyword(s):  
Finite Temperature ◽  
Self Energy

scholarly journals Identification of non-Fermi liquid fermionic self-energy from quantum Monte Carlo data

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Xiao Yan Xu ◽  
Avraham Klein ◽  
Kai Sun ◽  
Andrey V. Chubukov ◽  
Zi Yang Meng
Keyword(s):  
Monte Carlo ◽  
Finite Temperature ◽  
Quantum Monte Carlo ◽  
Fermi Liquid ◽  
Quantum Critical Point ◽  
Critical Metals ◽  
Monte Carlo Data ◽  
Low Frequencies ◽  
Self Energy ◽  
Quantum Critical

Abstract Quantum Monte Carlo (QMC) simulations of correlated electron systems provide unbiased information about system behavior at a quantum critical point (QCP) and can verify or disprove the existing theories of non-Fermi liquid (NFL) behavior at a QCP. However, simulations are carried out at a finite temperature, where quantum critical features are masked by finite-temperature effects. Here, we present a theoretical framework within which it is possible to separate thermal and quantum effects and extract the information about NFL physics at T = 0. We demonstrate our method for a specific example of 2D fermions near an Ising ferromagnetic QCP. We show that one can extract from QMC data the zero-temperature form of fermionic self-energy Σ(ω) even though the leading contribution to the self-energy comes from thermal effects. We find that the frequency dependence of Σ(ω) agrees well with the analytic form obtained within the Eliashberg theory of dynamical quantum criticality, and obeys ω2/3 scaling at low frequencies. Our results open up an avenue for QMC studies of quantum critical metals.

Two-loop vacuum polarization in QED at finite temperature

2015 ◽  
Vol 30 (34) ◽  
pp. 1550198
Author(s):  
Mahnaz Q. Haseeb ◽  
Samina S. Masood
Keyword(s):  
Finite Temperature ◽  
Vacuum Polarization ◽  
Renormalization Scheme ◽  
Point Of View ◽  
Electromagnetic Properties ◽  
Electron Mass ◽  
Debye Screening Length ◽  
Coupling Constant ◽  
Self Energy ◽  
Time Formalism

The self-energy of photons at finite temperature is presented, up to the two-loop corrections, using the real-time formalism. The renormalized coupling constant has been derived in a form that is relevant for all the temperature ranges of interest in QED, specifically for the temperatures around [Formula: see text], where [Formula: see text] is the electron mass. Finite temperature modification mainly comes through the hot fermions when [Formula: see text]. We use the calculations for the vacuum polarization to determine the dynamically generated mass of the photon, Debye screening length, and plasma frequency up to order [Formula: see text] as well as the electromagnetic properties of the background medium in the temperature range [Formula: see text]. At higher temperatures, the existing renormalization scheme does not work well because of the increase in the coupling constant. To exactly determine the validity of the renormalization scheme, the higher order calculations are required. The temperature, [Formula: see text], is of specific interest from the point of view of the early universe. Such calculations have also recently acquired significance due to the possibility of producing electron–positron plasma in the laboratory.

Single-Particle Self-Energy in Many-Body Systems at Finite Temperature

2000 ◽  
Vol 283 (2) ◽  
pp. 308-333 ◽  
Author(s):  
N. Giovanardi ◽  
P. Donati ◽  
P.F. Bortignon ◽  
R.A. Broglia
Keyword(s):  
Single Particle ◽  
Finite Temperature ◽  
Many Body ◽  
Self Energy ◽  
Many Body Systems

Phonon self-energy with layered anisotropy: Strong coupling finite temperature and impurities

1996 ◽  
Vol 74 (3-4) ◽  
pp. 159-171
Author(s):  
C. Jiang ◽  
J. P. Carbotte
Keyword(s):  
Superconducting State ◽  
Free Electron ◽  
Finite Temperature ◽  
Cylindrical Symmetry ◽  
Zero Temperature ◽  
Impurity Effects ◽  
Self Energy ◽  
Real Frequency ◽  
Coupling Strengths ◽  
Frequency Axis

We present a generalized, real frequency axis, Eliashberg formulation for the change in phonon self energy on entering the superconducting state which is valid for a solid with layered anisotropy. For simplicity, we assume free electron isotropic propagation in the planes with a hopping probability from plane to plane and cylindrical symmetry. Numerical results are given, at zero temperature, for different amounts of anisotropy and coupling strengths. Finite temperature and impurity effects are also considered.

scholarly journals PHOTON PROPAGATION IN THE CASIMIR VACUUM

2011 ◽  
Vol 20 (supp02) ◽  
pp. 182-187
Author(s):  
JAVIER PARDO VEGA ◽  
HUGO PÉREZ ROJAS
Keyword(s):  
Phase Velocity ◽  
Finite Temperature ◽  
Quantum Electrodynamics ◽  
Low Energy ◽  
Eigenvalues And Eigenvectors ◽  
Photon Propagation ◽  
Self Energy ◽  
Minkowskian Space ◽  
Independent Form ◽  
Qed Vacuum

A transformation that relates the Minkowskian space of Quantum Electrodynamics (QED) vacuum between parallel conducting plates and QED at finite temperature is obtained. From this formal analogy, the eigenvalues and eigenvectors of the photon self-energy for the QED vacuum between parallel conducting plates (Casimir vacuum) are found in an approximation independent form. It leads to two different physical eigenvalues and three eigenmodes. We also apply the transformation to derive the low energy photons phase velocity in the Casimir vacuum from its expression in the QED vacuum at finite temperature.

Sign in / Sign up

Export Citation Format

Share Document