Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hydrodynamic Evolution of Spherical Fireball In Relativistic Heavy Ion
  Collisions   Evolution process could be calculated from the relativistic hydrodynamic
equation with certain estimated initial conditions about a single spherical
fireball here. So one could estimate a kind of initial condition qualitatively
with a possible energy density about $\epsilon_0\approx 1.9$ $GeV/fm^3$, based
on this process to fit the experimental data at thermal freeze-out. The
evolution from a cylindrical fireball will be discussed simply in a later
chapter.

37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas