@article{19548,
  abstract     = {We consider the BCS energy gap „.T / (essentially given by „.T /  .T; p/,
the BCS order parameter) at all temperatures 0  T  Tc up to the critical one, Tc, and show
that, in the limit of weak coupling, the ratio „.T /=Tc is given by a universal function of the relative temperature T =Tc. On the one hand, this recovers a recent result by Langmann and Triola
[Phys. Rev. B 108 (2023), no. 10, article no. 104503] on three-dimensional s-wave superconductors for temperatures bounded uniformly away from Tc. On the other hand, our result lifts these
restrictions, as we consider arbitrary spatial dimensions d 2 ¹1; 2; 3º, discuss superconductors
with non-zero angular momentum (primarily in two dimensions), and treat the perhaps physically most interesting (due to the occurrence of the superconducting phase transition) regime of
temperatures close to Tc.

​
 .},
  author       = {Henheik, Sven Joscha and Lauritsen, Asbjørn Bækgaard},
  issn         = {1664-0403},
  journal      = {Journal of Spectral Theory},
  number       = {1},
  pages        = {305–352},
  publisher    = {EMS Press},
  title        = {{Universal behavior of the BCS energy gap}},
  doi          = {10.4171/JST/540},
  volume       = {15},
  year         = {2025},
}