Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Galaxy clusters, cosmic chronometers and the Einstein equivalence
  principle   The Einstein equivalence principle in the electromagnetic sector can be
violated in modifications of gravity theory generated by a multiplicative
coupling of a scalar field to the electromagnetic Lagrangian. In such theories,
deviations of the standard result for the cosmic distance duality relation, and
a variation of the fine structure constant are expected and are unequivocally
intertwined. In this paper, we search for these possible cosmological
signatures by using galaxy cluster gas mass fraction measurements and cosmic
chronometers. No significant departure from general relativity is found
regardless of our assumptions about cosmic curvature or a possible depletion
factor evolution in cluster measurements.

7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg