Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Screening Vector Field Modifications of General Relativity   A screening mechanism for conformal vector-tensor modifications of general
relativity is proposed. The conformal factor depends on the norm of the vector
field and makes the field to vanish in high dense regions, whereas drives it to
a non-null value in low density environments. Such process occurs due to a
spontaneous symmetry breaking mechanism and gives rise to both the screening of
fifth forces as well as Lorentz violations. The cosmology and local constraints
are also computed.

2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th