Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An electric-field representation of the harmonic XY model   The two-dimensional harmonic XY (HXY) model is a spin model in which the
classical spins interact via a piecewise parabolic potential. We argue that the
HXY model should be regarded as the canonical classical lattice spin model of
phase fluctuations in two-dimensional condensates, as it is the simplest model
that guarantees the modular symmetry of the experimental systems. Here we
formulate a lattice electric-field representation of the HXY model and contrast
this with an analogous representation of the Villain model and the
two-dimensional Coulomb gas with a purely rotational auxiliary field. We find
that the HXY model is a spin-model analogue of a lattice electric-field model
of the Coulomb gas with an auxiliary field, but with a temperature-dependent
vacuum (electric) permittivity that encodes the coupling of the spin vortices
to their background spin-wave medium. The spin vortices map to the Coulomb
charges, while the spin-wave fluctuations correspond to auxiliary-field
fluctuations. The coupling explains the striking differences in the
high-temperature asymptotes of the specific heats of the HXY model and the
Coulomb gas with an auxiliary field. Our results elucidate the propagation of
effective long-range interactions throughout the HXY model (whose interactions
are purely local) by the lattice electric fields. They also imply that global
spin-twist excitations (topological-sector fluctuations) generated by local
spin dynamics are ergodically excluded in the low-temperature phase. We discuss
the relevance of these results to condensate physics.

31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
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
0
The categories of this paper are: hep-ph