Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Query on Negative Temperature, Internal Interactions and Decrease of
  Entropy   After negative temperature is restated, we find that it will derive
necessarily decrease of entropy. Negative temperature is based on the Kelvin
scale and the condition dU>0 and dS<0. Conversely, there is also negative
temperature for dU<0 and dS>0. But, negative temperature is contradiction with
usual meaning of temperature and with some basic concepts of physics and
mathematics. It is a question in nonequilibrium thermodynamics. We proposed a
possibility of decrease of entropy due to fluctuation magnified and internal
interactions in some isolated systems. From this we discuss some possible
examples and theories.

2
The categories of this paper are: math
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat