Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The effect of universe inhomogeneities on cosmological distance
  measurements   Using the focusing equation, the equation for the cosmological angular
diameter distance is derived, based on the ideas of Academician Ya.B.
Zel'dovich, namely, that the distribution of matter at small angles is not
homogeneous, and the light cone is close to being empty. We propose some ways
of testing a method for measuring the angular diameter distances and show that
the proposed method leads to results that agree better with the experimental
data than those obtained by the usual methods.

3
The categories of this paper are: physics
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio