Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Kerr theorem, Kerr-Schild formalizm and multiparticle Kerr-Schild
  solutions   We consider an extended version of the Kerr theorem incorporated in the
Kerr-Schild formalism. It allows one to construct the series of exact solutions
of the Einstein-Maxwell field equations from a holomorphic generating function
$F$ of twistor variables. The exact multiparticle Kerr-Schild solutions are
obtained from generating function of the form $F=\prod_i^k F_i, $ where $F_i$
are partial generating functions for the spinning particles $ i=1...k$.
Gravitational and electromagnetic interaction of the spinning particles occurs
via the light-like singular twistor lines. As a result, each spinning particle
turns out to be `dressed' by singular pp-strings connecting it to other
particles. Physical interpretation of this solution is discussed.

12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
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The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
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The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga