Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Low Matter Density Decaying Vacuum Cosmology from Complex Metric   A low matter density decaying vacuum cosmology is proposed on the assumption
that the universe's radius is a complex quantity \hat{R} if it is regarded as
having a zero energy-momentum tensor. But we find that when the radius is real,
it contains matter. Using the Einstein-Hilbert action principle, the physical
scale factor R(t) =|\hat{R}| is obtained as equal to (R_0^{2} + t^{2})^{1/2}
with R_0 representing the finite radius of the universe at t=0. The resulting
physical picture is roughly a theoretical justification of the old Ozer-Taha
model. The new model is devoid of all cosmological problems. In particular, it
confirms the bounds on H_p, the present value of the Hubble parameter: 0.85 <
H_p t_p < 1.91 and faces no age problem. We argue that the total energy density
consists of parts corresponding to relativistic/non-relativistic matter, a
positive vacuum energy and a form of matter with equation of state p_K = -(1/3)
rho_K (textures or generally K-matter), and the following predictions are made
for the present nonrelativistic era: Omega_{M,n.rel.} \approx 2/3,
Omega_{V,n.rel.} \approx 1/3, Omega_ <<1, Omega_K \approx 1, where a parameter
corresponding to K-matter is taken to be unity. It is shown that the spacetime
with complex metric has signature changing properties. Using quantum
cosmological considerations, it is shown that the wave function is peaked about
the classical contour of evolution and the minimum radius R_0 of the
nonsingular model is predicted as comparable with the Planck length.
  PACS No(s); 98.80 Hw, 04.20, 04.60

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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-th
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The categories of this paper are: nlin
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The categories of this paper are: eess
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The categories of this paper are: math
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The categories of this paper are: quant-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: funct-an
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The categories of this paper are: cond-mat
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The categories of this paper are: econ
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The categories of this paper are: bayes-an