Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cosmological Studies from Radio Source Samples   I review some recent cosmological studies based on redshift surveys of radio
sources selected at low frequencies. The accretion rate onto the central black
hole is identified as the basis of a crude physical division of the
low-frequency population into two sub-populations: the first comprises
`Eddington-tuned' (high accretion rate) quasars and their torus-hidden
counterparts; the second comprises `starved quasars' like M87. There exist
remarkable similarities between the shapes and evolutionary behaviours of the
luminosity functions of radio sources and radio-quiet quasars; all luminous AGN
are $\sim300-$times rarer at epochs corresponding to $z \sim 0$ than at $z \sim
2.5$. I argue that any evidence that quasars were intrinsically rarer at $z
\sim 5$ than at $z \sim 2.5$ is as yet both tentative and indirect. A simple
calculation suggests that the radio source population has been over-looked as a
potentially important contributor to the entropy budget of the Universe. A
recent sub-mm survey of radio sources is used to demonstrate a connection
between the events which trigger jets and intense bursts of star formation, and
a close link between the histories of star formation and AGN activity is
proposed. I discuss the aims and methods of future large redshift surveys of
radio sources, emphasising the importance of dovetailing these with the
development of robust physical models for radio sources and their
epoch-dependent environments.

22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys