Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Surface Layers in General Relativity and Their Relation to Surface
  Tensions   For a thin shell, the intrinsic 3-pressure will be shown to be analogous to
-A, where A is the classical surface tension: First, interior and exterior
Schwarzschild solutions will be matched together such that the surface layer
generated at the common boundary has no gravitational mass; then its intrinsic
3-pressure represents a surface tension fulfilling Kelvin's relation between
mean curvature and pressure difference in the Newtonian limit. Second, after a
suitable definition of mean curvature, the general relativistic analogue to
Kelvin's relation will be proven to be contained in the equation of motion of
the surface layer.

9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph