Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unconstrained SU(2) Yang-Mills Theory with Topological Term in the
  Long-Wavelength Approximation   The Hamiltonian reduction of SU(2) Yang-Mills theory for an arbitrary \theta
angle to an unconstrained nonlocal theory of a self-interacting positive
definite symmetric 3 \times 3 matrix field S(x) is performed. It is shown that,
after exact projection to a reduced phase space, the density of the Pontryagin
index remains a pure divergence, proving the \theta independence of the
unconstrained theory obtained. An expansion of the nonlocal kinetic part of the
Hamiltonian in powers of the inverse coupling constant and truncation to lowest
order, however, lead to violation of the \theta independence of the theory. In
order to maintain this property on the level of the local approximate theory, a
modified expansion in the inverse coupling constant is suggested, which for a
vanishing \theta angle coincides with the original expansion. The corresponding
approximate Lagrangian up to second order in derivatives is obtained, and the
explicit form of the unconstrained analogue of the Chern-Simons current linear
in derivatives is given. Finally, for the case of degenerate field
configurations S(x) with rank|S| = 1, a nonlinear \sigma-type model is
obtained, with the Pontryagin topological term reducing to the Hopf invariant
of the mapping from the three-sphere S^3 to the unit two-sphere S^2 in the
Whitehead form.

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The categories of this paper are: dg-ga
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an