We present a novel solution method with which we obtain the spectral functions of the attractive Hubbard model in two dimensions in a non self-consistent formulation of the T-matrix approximation. We use a partial fraction decomposition of the self energy from which we obtain the single-particle spectral functions to a remarkably high accuracy. Here we find the poles and residues of the self energy to a relative accuracy of 10-80 for an 8×8 lattice, and plot the resulting density of states. Our results show pseudogap physics as Tc is approached from above; these analytical results are in agreement with recent Quantum Monte Carlo data.

@article{
  title = {New solutions of the T-matrix theory of the attractive Hubbard model},
  author = {Beach, K. S. D. and Gooding, R. J. and Marsiglio, F.}
  journal = {Physica C: Superconductivity},
  volume = {341--348, Part 2},
  pages = {897--898},
  year = {2000},
  issn = {0921-4534},
  doi = {10.1016/S0921-4534(00)00724-3},
  url = {https://www.sciencedirect.com/science/article/abs/pii/S0921453400007243}
}