Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Deforming Black Hole and Cosmological Solutions by Quasiperiodic and/or
  Pattern Forming Structures in Modified and Einstein Gravity   We elaborate on the anholonomic frame deformation method, AFDM, for
constructing exact solutions with quasiperiodic structure in modified gravity
theories, MGTs, and general relativity, GR. Such solutions are described by
generic off-diagonal metrics, nonlinear and linear connections and (effective)
matter sources with coefficients depending on all spacetime coordinates via
corresponding classes of generation and integration functions and (effective)
matter sources. There are studied effective free energy functionals and
nonlinear evolution equations for generating off-diagonal quasiperiodic
deformations of black hole and/or homogeneous cosmological metrics. The
physical data for such functionals are stated by different values of constants
and prescribed symmetries for defining quasiperiodic structures at cosmological
scales, or astrophysical objects in nontrivial gravitational backgrounds some
similar forms as in condensed matter physics. It is shown how quasiperiodic
structures determined by general nonlinear, or additive, functionals for
generating functions and (effective) sources may transform black hole like
configurations into cosmological metrics and inversely. We speculate on
possible implications of quasiperiodic solutions in dark energy and dark matter
physics. Finally, it is concluded that geometric methods for constructing exact
solutions consist an important alternative tool to numerical relativity for
investigating nonlinear effects in astrophysics and cosmology.

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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: hep-ex
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The categories of this paper are: hep-ph
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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: q-bio
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: cond-mat