Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Relativistic Kinetic Equations for Finite Domains and Freeze-out Problem   The relativistic kinetic equations for the two domains separated by the
hypersurface with both space- and time-like parts are derived. The particle
exchange between the domains separated by the time-like boundaries generates
source terms and modifies the collision term of the kinetic equation. The
correct hydrodynamic equations for the ``hydro+cascade'' models are obtained
and their differences from existing freeze-out models of the hadronic matter
are discussed.

9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
19
The categories of this paper are: eess
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom