Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The asymmetric single-impurity Anderson model - the modified
  perturbation theory   We investigate the single-impurity Anderson model by means of the recently
introduced modified perturbation theory. This approximation scheme yields
reasonable results away from the symmetric case. The agreement with exactly
known results for the symmetric case is checked, and results for the
non-symmetric case are presented. With decreasing conduction band occupation,
the breakdown of the screening of the local moment is observed. In the
crossover regime between Kondo limit and mixed-valence regime, an enhanced
zero-temperature susceptibility is found.

22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci