Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fast, higher-order direct/iterative hybrid solver for scattering by
  Inhomogeneous media -- with application to high-frequency and discontinuous
  refractivity problems   This paper presents a fast high-order method for the solution of
two-dimensional problems of scattering by penetrable inhomogeneous media, with
application to high-frequency configurations containing (possibly)
discontinuous refractivities. The method relies on a combination of a
differential volumetric formulation and a boundary integral formulation. Thus,
in the proposed approach the entire computational domain is partitioned into
large numbers of volumetric spectral approximation patches which are then
grouped into patch subsets for local direct solution; the interactions with the
exterior domain are handled by means of a boundary integral equation. The
resulting algorithm can be quite effective: after a modestly-demanding
precomputation stage (whose results for a given frequency can be repeatedly
used for arbitrarily chosen incidence angles), the proposed algorithm can
accurately evaluate scattering by configurations including large and complex
objects and/or high refractivity contrasts, including possibly refractive-index
discontinuities, in fast single-core runs.

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The categories of this paper are: physics
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The categories of this paper are: stat
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
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The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc
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The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
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The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
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The categories of this paper are: q-bio
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The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga