Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cosmic evolution of gas content and accretion   In the present universe, the gas is a minor component of giant galaxies, and
its dominant phase is atomic (HI). During galaxy evolution in cosmic times,
models predict that gas fractions were much higher in galaxies, and gas phases
could be more balanced between molecular (H2) and atomic (HI). This gaseous
evolution is certainly a key factor to explain the cosmic evolution of the star
formation rate density. Star formation efficiency might also vary with
redshift, and the relative importance of these factors is not yet well known.
Our current knowledge of cosmic evolution of gas from molecular observations at
high-z is reviewed and confronted to simulations.

24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph