Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Chemical Evolution of the Universe I: High Column Density Absorbers   We construct a simple, robust model of the chemical evolution of galaxies
from high to low redshift, and apply it to published observations of damped
Lyman-alpha quasar absorption line systems (DLAs). The elementary model assumes
quiescent star formation and isolated galaxies (no interactions, mergers or gas
flows). We consider the influence of dust and chemical gradients in the
galaxies, and hence explore the selection effects in quasar surveys. We fit
individual DLA systems to predict some observable properties of the absorbing
galaxies, and also indicate the expected redshift behaviour of chemical element
ratios involving nucleosynthetic time delays.
  Despite its simplicity, our `monolithic collapse' model gives a good account
of the distribution and evolution of the metallicity and column density of
DLAs, and of the evolution of the global star formation rate and gas density
below redshifts z 3. However, from the comparison of DLA observations with our
model, it is clear that star formation rates at higher redshifts (z>3) are
enhanced. Galaxy interactions and mergers, and gas flows very probably play a
major role.

12
The categories of this paper are: nucl-th
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
1
The categories of this paper are: cs
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph