Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Interferometric Parallax: A Method for Measurement of Astronomical
  Distances   We show that distances of objects at cosmological distances can be measured
directly using interferometry. Our approach to interferometric parallax comes
from analysis of 4-point amplitude and intensity correlations that can be
generated from pairs of well-separated detectors. The baseline required to
measure cosmological distances of Gigaparsec order are within the reach of the
next generation of space-borne detectors. The semi-classical interpretation of
intensity correlations uses a notion of a single photon taking two paths
simultaneously. Semi-classically a single photon can simultaneously enter four
detectors separated by an astronomical unit, developing correlations feasible
to measure with current technology.

10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con