Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Thermodynamics of isotropic and anisotropic layered magnets:
  renormalization group approach and 1/N expansion   The O(N) model of layered antiferro- and ferromagnets with a weak interlayer
coupling and/or easy-axis anisotropy is considered. A renormalization group
(RG) analysis in this model is performed, the results for N=3 being expected to
agree with those of the 1/M expansion in the CP^{M-1} model at M=2. The quantum
and classical cases are considered. A crossover from an isotropic 2D-like to 3D
Heisenberg (or 2D Ising) regime is investigated within the 1/N expansion.
Analytical results for the temperature dependence of the (sublattice)
magnetization are obtained in different regimes. The RG results for the
ordering temperature are derived. In the quantum case they coincide with the
corresponding results of the 1/N expansion. The numerical calculations on the
base of the equations obtained yield a good agreement with experimental data on
the layered perovskites La2CuO4, K2NiF4 and Rb2NiF4, and the Monte Carlo
results for the anisotropic classical systems.

8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci