Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Particle Production in Matrix Cosmology   We consider cosmological particle production in 1+1 dimensional string
theory. The process is described most efficiently in terms of anomalies, but we
also discuss the explicit mode expansions. In matrix cosmology the usual vacuum
ambiguity of quantum fields in time-dependent backgrounds is resolved by the
underlying matrix model. This leads to a finite energy density for the "in"
state which cancels the effect of anomalous particle production.

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The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
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The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
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The categories of this paper are: cmp-lg
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The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph