Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Laser Communication with Proxima and Alpha Centauri using the Solar
  Gravitational Lens   A search was conducted for laser signals, both sub-second pulses and
continuous emission, from the regions of the sky opposite Proxima and Alpha
Centauri. These regions are located at the foci of the gravitational lensing
caused by the Sun, ideal for amplifying transmissions between our Solar System
and those two nearest stellar neighbors. During six months in 2020 and 2021,
88000 exposures for Proxima Cen and 47000 exposures for Alpha Cen were
obtained. No evidence was detected of light pulses or continuous laser emission
in the wavelength range of 380 to 950 nm. We would have detected a laser having
a power of just 100 Watts.

10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph