Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Breakthrough Listen Search for Intelligent Life: A 3.95-8.00 GHz
  Search for Radio Technosignatures in the Restricted Earth Transit Zone   We report on a search for artificial narrowband signals of 20 stars within
the restricted Earth Transit Zone as a part of the ten-year Breakthrough Listen
(BL) search for extraterrestrial intelligence. The restricted Earth Transit
Zone is the region of the sky from which an observer would see the Earth
transit the Sun with an impact parameter of less than 0.5. This region of the
sky is geometrically unique, providing a potential way for an extraterrestrial
intelligence to discover the Solar System. The targets were nearby (7-143 pc)
and the search covered an electromagnetic frequency range of 3.95-8.00 GHz. We
used the Robert C. Byrd Green Bank Telescope to perform these observations with
the standard BL data recorder. We searched these data for artificial narrowband
($\sim$Hz) signals with Doppler drift rates of $\pm 20$ Hz s$^{-1}$. We found
one set of potential candidate signals on the target HIP 109656 which was then
found to be consistent with known properties of anthropogenic radio frequency
interference. We find no evidence for radio technosignatures from
extraterrestrial intelligence in our observations. The observing campaign
achieved a minimum detectable flux which would have allowed detections of
emissions that were $10^{-3}$ to $0.88$ times as powerful as the signaling
capability of the Arecibo radar transmitter, for the nearest and furthest stars
respectively. We conclude that at least $8\%$ of the systems in the restricted
Earth Transit Zone within 150 pc do not possess the type of transmitters
searched in this survey. To our knowledge, this is the first targeted search
for extraterrestrial intelligence of the restricted Earth Transit Zone. All
data used in this paper are publicly available via the Breakthrough Listen
Public Data Archive (http://seti.berkeley.edu/bldr2).

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The categories of this paper are: physics
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The categories of this paper are: math
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The categories of this paper are: econ
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: adap-org
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The categories of this paper are: quant-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: ao-sci
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: hep-lat