Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Black Hole Genesis and origin of cosmic acceleration   We consider a hypothesis that the closed Universe was formed on the other
side of the event horizon of a black hole existing in another universe. That
black hole appears in the Universe as a boundary white hole, and its rest frame
in comoving coordinates is a frame of reference in which the cosmic microwave
background is isotropic. We consider the Lagrangian density for the
gravitational field that is proportional to the curvature scalar, and use the
metric-affine variational principle in which the symmetric affine connection
and the metric tensor are variables. The white hole appears in the Lagrangian
through a simplest, generally covariant and linear term: the four-divergence of
the four-velocity of the white hole in comoving coordinates. We show that the
variation of the action with respect to the connection generates the
nonmetricity, which creates a term in the Lagrangian that is equivalent to a
positive cosmological constant. The current cosmic acceleration may therefore
be a manifestation of the boundary of the closed Universe. We also show that
the equation of motion of a test particle deviates from the geodesic equation
by a term that depends on the four-velocities of the particle and the white
hole. The rest frame of the white hole in comoving coordinates is the only
absolutely inertial frame of reference. This deviation might be observed on
galactic scales.

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The categories of this paper are: patt-sol
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-th
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The categories of this paper are: funct-an
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The categories of this paper are: physics
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The categories of this paper are: ao-sci
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The categories of this paper are: supr-con
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-alg
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The categories of this paper are: cmp-lg
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: math-ph