Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Einstein clusters as models of inhomogeneous spacetimes   We study the effect of small-scale inhomogeneities for Einstein clusters. We
construct a spherically symmetric stationary spacetime with small-scale radial
inhomogeneities and propose the Gedankenexperiment. An hypothetical observer at
the center constructs, using limited observational knowledge, a simplified
homogeneous model of the configuration. An idealization introduces side
effects. The inhomogeneous spacetime and the effective homogeneous spacetime
are given by simple solutions to Einstein equations. They provide a basic
toy-model for studies of the effect of small-scale inhomogeneities in general
relativity. We show that within our highly inhomogeneous model the effect of
small-scale inhomogeneities remains small for a central observer. The
homogeneous model fits very well to all hypothetical observations as long as
their precision is not high enough to reveal a tension.

10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con