Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optimization of alloy-analogy-based approaches to the
  infinite-dimensional Hubbard model   An analytical expression for the self-energy of the infinite-dimensional
Hubbard model is proposed that interpolates between different exactly solvable
limits. We profit by the combination of two recent approaches that are based on
the alloy-analogy (Hubbard-III) solution: The modified alloy-analogy (MAA)
which focuses on the strong-coupling regime, and the Edwards-Hertz approach
(EHA) which correctly recovers the weak-coupling regime. Investigating the
high-energy expansion of the EHA self-energy, it turns out that the EHA
reproduces the first three exactly known moments of the spectral density only.
This may be insufficient for the investigation of spontaneous magnetism. The
analysis of the high-energy behavior of the CPA self-consistency equation
allows for a new interpretation of the MAA: The MAA is the only (two-component)
alloy-analogy that correctly takes into account the first four moments of the
spectral density. For small U, however, the MAA does not reproduce Fermi-liquid
properties. The defects of the MAA as well as of the EHA are avoided in the new
approach. We discuss the prospects of the theory and present numerical results
in comparison with essentially exact quantum Monte Carlo data. The correct
high-energy behavior of the self-energy is proved to be a decisive ingredient
for a reliable description of spontaneous magnetism.

33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci