Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: New Constraints from High Redshift Supernovae and Lensing Statistics
  upon Scalar Field Cosmologies   We explore the implications of gravitationally lensed QSOs and high-redshift
SNe Ia observations for spatially flat cosmological models in which a
classically evolving scalar field currently dominates the energy density of the
Universe. We consider two representative scalar field potentials that give rise
to effective decaying $\Lambda $ (``quintessence'') models:
pseudo-Nambu-Goldstone bosons ($V(\phi)=M^4(1+\cos (\phi /f)) $) and an inverse
power-law potential ($V(\phi)=M^{4+\alpha}\phi ^{-\alpha}$). We show that a
large region of parameter space is consistent with current data if $\Omega_{m0}
> 0.15$. On the other hand, a higher lower bound for the matter density
parameter suggested by large-scale galaxy flows, $\Omega_{m0} > 0.3$,
considerably reduces the allowed parameter space, forcing the scalar field
behavior to approach that of a cosmological constant.

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The categories of this paper are: solv-int
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The categories of this paper are: gr-qc
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The categories of this paper are: quant-ph
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The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
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The categories of this paper are: patt-sol
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The categories of this paper are: math
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The categories of this paper are: chao-dyn
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The categories of this paper are: stat
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: q-alg
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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas
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The categories of this paper are: acc-phys