Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Static elastic shells in Einsteinian and Newtonian gravity   We study the behaviour of a specific system of relativistic elasticity in its
own gravitational field: a static, spherically symmetric shell whose wall is of
arbitrary thickness consisting of hyperelastic material. We give the system of
field equations and boundary conditions within the framework of the Einsteinian
theory of gravity. Furthermore, we analize the situation in the Newtonian
theory of gravity and obtain an existence result valid for small gravitational
constants and pointwise stability by using the implicit function theorem. If
one replaces the elastic material with a fluid, one finds that stable states
can not exist.

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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
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The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
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The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
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The categories of this paper are: nlin
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The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci