Finite-temperature<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>T</mml:mi></mml:math>matrix in a real-time formalism

Abstract. We study the dynamical equation of the time-ordered Green's function at finite temperature. We show that the time-ordered Green's function obeys a conventional Dyson equation only at equilibrium and in the limit of zero-temperature. In all other cases, i.e. finite-temperature at equilibrium or non-equilibrium, the timeordered Green's function obeys instead a modified Dyson equation. The derivation of this result is obtained from the general formalism of the non-equilibrium Green's functions on the Keldysh time-loop contour. At equilibrium, our result is fully consistent with the Matsubara temperature Green's function formalism and also justifies rigorously the correction terms introduced in an ad hoc way with Hedin and Lundqvist. Our results show that one should use the appropriate dynamical equation for the time-ordered Green's function when working beyond the equilibrium zero-temperature limit.

show abstract

“…Such temperature effects were also found for the T -matrix approximation in a real-time formalism in Ref. [33].…”

Section: Discussionsupporting

confidence: 66%

“…Beyond the zero temperature, correction terms in the Dyson equation for G t (ω) must be taken into account, or one needs to work with the Matsubara formalism for G(iω n ). Such temperature effects were also found for the T-matrix approximation in a real-time formalism in [31].…”

Section: Discussionsupporting

confidence: 63%

Dynamical equations for time-ordered Green’s functions: from the Keldysh time-loop contour to equilibrium at finite and zero temperature

Ness

Dash

2012

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…The closed-time path formalism (Schwinger 1961and, e.g., Mahanthappa 1962, Canivelli et al 1978, Zhou et all985, Calzetta and Hu 1987, Manoukian 1987, 1991 of quantum field theory (QFT) has been a useful tool in performing expectation values such as transition probabilities without evaluating first transition amplitudes.…”

mentioning

confidence: 99%

Derivation of the closed-time path of quantum field theory at finite temperatures

Manoukian¹

1991

J. Phys. G: Nucl. Part. Phys.

View full text Add to dashboard Cite

Absbd.A derivation of the closed-time path formalism of quantum field theory is given at finite temperatures. The derivation is based on a solution found for the diagonal element of the closed-time path transition amplitudes at zero temperatures, the performance of an averaging over the temperature-dependent statistical distribution and finally the application of the action principle for a closed-time path.

show abstract

A note on Keldysh's perturbation formalism

Boer

Weert

1979

Physica A: Statistical Mechanics and its Applications

View full text Add to dashboard Cite

Finite-temperatureTmatrix in a real-time formalism

Cited by 6 publications

References 21 publications

Dynamical equations for time-ordered Green’s functions: from the Keldysh time-loop contour to equilibrium at finite and zero temperature

Dynamical equations for time-ordered Green’s functions: from the Keldysh time-loop contour to equilibrium at finite and zero temperature

Derivation of the closed-time path of quantum field theory at finite temperatures

A note on Keldysh's perturbation formalism

Contact Info

Product

Resources

About