Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Silhouette of M87*: A new window to peek into the world of hidden
  dimensions   The recent observation of the shadow of the supermassive black hole M87*,
located at the centre of the M87 galaxy, by the Event Horizon Telescope
collaboration has opened up a new window to probe the strong gravity regime. In
this letter, we explicitly demonstrate the consequences of this observation on
brane world black holes, characterized by existence of a negative tidal charge.
Our results based on three observables associated with the shadow, namely,
angular diameter, deviation from circularity and axis ratio reveal that the
existence of a negative tidal charge is more favoured, possibly marking a
deviation from general relativity.

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The categories of this paper are: bayes-an
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol