Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Momentum structure of the self-energy and its parametrization for the
  two-dimensional Hubbard model   We compute the self-energy for the half-filled Hubbard model on a square
lattice using lattice quantum Monte Carlo simulations and the dynamical vertex
approximation. The self-energy is strongly momentum dependent, but it can be
parametrized via the non-interacting energy-momentum dispersion
$\varepsilon_{\mathbf{k}}$, except for pseudogap features right at the Fermi
edge. That is, it can be written as $\Sigma(\varepsilon_{\mathbf{k}},\omega)$,
with two energy-like parameters ($\varepsilon$, $\omega$) instead of three
($k_x$, $k_y$ and $\omega$). The self-energy has two rather broad and weakly
dispersing high energy features and a sharp $\omega= \varepsilon_{\mathbf{k}}$
feature at high temperatures, which turns to $\omega=
-\varepsilon_{\mathbf{k}}$ at low temperatures. Altogether this yields a Z- and
reversed-Z-like structure, respectively, for the imaginary part of
$\Sigma(\varepsilon_{\mathbf{k}},\omega)$. We attribute the change of the low
energy structure to antiferromagnetic spin fluctuations.

1
The categories of this paper are: cs
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics