Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectral Gap and Decay of Correlations in U(1)-Symmetric Lattice Systems
  in Dimensions D<2   We consider many-body systems with a global U(1) symmetry on a class of
lattices with the (fractal) dimensions D<2 and their zero temperature
correlations whose observables behave as a vector under the U(1) rotation. For
a wide class of the models, we prove that if there exists a spectral gap above
the ground state, then the correlation functions have a stretched exponentially
decaying upper bound. This is an extension of the McBryan-Spencer method at
finite temperatures to zero temperature. The class includes quantum spin and
electron models on the lattices, and our method also allows finite or infinite
(quasi)degeneracy of the ground state. The resulting bounds rule out the
possibility of the corresponding magnetic and electric long-range order.

25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
3
The categories of this paper are: physics
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con