Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Heisenberg Antiferromagnets versus Nonlinear $\sigma$ Model
  Without the Large S Limit   In this letter, I develop a new topologically invariant coherent state path
integral for spin systems, and apply it to the quantum Heisenberg model on a
square lattice. As a result, the quantum nonlinear $\sigma$ model for arbitrary
values of spin can be directly obtained. The effective coupling constant and
spin wave velocity are modified by $g_s= {2\over S}\sqrt{d+{T_\Lambda\over
2SJ}}$ and $c_s=2JSa \sqrt{d+{T_\Lambda\over 2SJ}}$, where $T_\Lambda$ is a
natural temperature scale for the reliability of the theory. The formulation
can also be extended to other generalized coherent state path integrals.

36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th