Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Decreasing critical temperature of gas BEC in spatially periodic
  potential and relevance to experiments treated by Mott-Hubbard model   It is shown that the critical temperature of gas Bose-Einstein condensation
decreases in deepening periodic potential, in contrast to common regularity in
a separate potential well. The physical explanation of this phenomenon is
given. Characteristic scale of potential energies decaying the critical
temperature is the quantum recoil energy of periodic potential. The theory
represents an alternative and direct approach to the experimental results
(C.Orzel et al Science 291, 2386 (2001); M.Greiner et al, Nature 415, 39
(2002)) obtained with BEC in optical lattices and treated as the phase
squeezing or Mott transition processes.

12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
1
The categories of this paper are: cs
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph