Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the violation of the Fermi-liquid picture in two-dimensional systems
  owing to the Van-Hove singularities   We consider the two-dimensional t-t' Hubbard model with the Fermi level being
close to the van Hove singularities. The phase diagram of the model is
discussed. In a broad energy region the self-energy at the singularity points
has a nearly-linear energy dependence. The corresponding correction to the
density of states is proportional to ln^3(e). Both real- and imaginary part of
the self-energy increase near the quantum phase transition into magnetically
ordered or superconducting phase which implies violation of the Fermi-liquid
behavior. The application of the results to cuprates is discussed.

2
The categories of this paper are: math
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs