Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Full-bandwidth Eliashberg theory of superconductivity beyond Migdal's
  approximation   We solve the anisotropic, full-bandwidth and non-adiabatic Eliashberg
equations for phonon-mediated superconductivity by fully including the first
vertex correction in the electronic self-energy. The non-adiabatic equations
are solved numerically here without further approximations, for a one-band
model system. We compare the results to those that we obtain by adiabatic
full-bandwidth, as well as Fermi-surface restricted Eliashberg-theory
calculations. We find that non-adiabatic contributions to the superconducting
gap can be positive, negative or negligible, depending on the dimensionality of
the considered system, the degree of non-adiabaticity, and the coupling
strength. We further examine non-adiabatic effects on the transition
temperature and the electron-phonon coupling constant. Our treatment emphasizes
the importance of overcoming previously employed approximations in estimating
the impact of vertex corrections on superconductivity and opens a pathway to
systematically study vertex correction effects in systems such as high-$T_c$,
flat band and low-carrier density superconductors.

15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg