Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Enhanced interaction effects in the vicinity of the topological
  transition   A metal near the topological transition can be loosely viewed as consisting
of two groups of electrons. First group are "bulk" electrons occupying most of
the Brillouin zone. Second group are electrons with wave vectors close to the
topological transition point. Kinetic energy, $\tilde{E}_F$, of electrons of
the first group is much bigger than kinetic energy, $E_F$, of electrons of the
second group. With electrons of the second group being slow, the interaction
effects are more pronounced for these electrons. We perform a calculation
illustrating that electrons of the second group are responsible for inelastic
lifetime making it anomalously short, so that the concept of quasiparticles
applies to these electrons only marginally. We also demonstrate that
interactions renormalize the spectrum of electrons in the vicinity of
topological transition, the parameters of renormalized spectrum being strongly
dependent on the proximity to the transition. Another many-body effect that
evolves dramatically as the Fermi level is swept through the transition is the
Friedel oscillations of the electron density created by electrons of the second
group around an impurity. These oscillations are strongly anisotropic with a
period depending on the direction. Scattering of electrons off these
oscillations give rise to a temperature-dependent ballistic correction to the
conductivity.

29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics