A general theory of superconductivity is formulated within the thermodynamic Green function method for various types of pairing mediated by phonons, spin fluctuations, and strong Coulomb correlations in the Hubbard and t-J models. A rigorous Dyson equation for matrix Green functions is derived in terms of a self-energy as a many-particle Green function. By applying the noncrossing approximation...

References lated-urls http://rspa.royalsocietypublishing.org/content/463/2086/2709.full.html#re Article cited in: html#ref-list-1 http://rspa.royalsocietypublishing.org/content/463/2086/2709.full. This article cites 19 articles, 1 of which can be accessed free Email alerting service here the box at the top right-hand corner of the article or click Receive free email alerts when new articles cit...

Necessary and sufficient conditions for Lipschitzness of the Lempert and Green functions are found in terms of their boundary behaviors.

We investigate the possibility to assist the numerically ill-posed calculation of spectral properties of interacting quantum systems in thermal equilibrium by extending the imaginary-time simulation to a finite Schwinger-Keldysh contour. The effect of this extension is tested within the standard maximum entropy approach to analytic continuation. We find that the inclusion of real-time data impr...

Previous results on fermion chirality-flipping four-point functions are extended to SU(N) gauge theories. The problem is purely non-perturbative, and it is approached by truncating the Schwinger-Dyson hierarchy. The large-N limit also simplifies the problem substantially. The resulting equation is solved numerically by relaxation techniques and an estimate of the critical coupling and momentum ...

The properties of the various types of bosonic Green functions at finite temperature in the zero energy limit are considered in the light of recent work. Nous discutons, à la lumière de récents travaux, des propriétés de certains types de fonctions de Green à température finie, dans le cas limite où l’énergie est nulle.

Quantization of electrodynamics in curved space-time in the Lorenz gauge and with arbitrary gauge parameter makes it necessary to study Green functions of non-minimal operators with variable coefficients. Starting from the integral representation of photon Green functions, we link them to the evaluation of integrals involving Γ-functions. Eventually, the full asymptotic expansion of the Feynman...

The study of biharmonic functions under the ordinary (Euclidean) Laplace operator on the open unit disk D in C arises in connection with plate theory, and in particular, with the biharmonic Green functions which measure, subject to various boundary conditions, the deflection at one point due to a load placed at another point. A homogeneous tree T is widely considered as a discrete analogue of t...