Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Neutron displacement noise-free interferometer for gravitational-wave
  detection   An interferometer design that cancels all displacement noises of its test
masses and maintains a gravitational-wave (GW) signal by combining multiple
detector signals is called a displacement noise-free interferometer (DFI). The
idea has been considered previously for a laser interferometer. However, a
limitation of a laser DFI is that its sensitive frequency band is too high for
astrophysical GW sources, $\sim 10^5\,{\rm Hz}$ even for a kilometer-sized
interferometer. To circumvent this limitation, in this letter, we propose a
neutron DFI, in which neutrons are used instead of light. Since neutrons have
velocities much lower than the speed of light, the sensitive frequency band of
a neutron DFI can be lowered down to $\sim 10^{-1}\,{\rm Hz}$. Therefore, a
neutron DFI can be utilized for detecting GWs that are inaccessible by an
ordinary laser interferometer on the ground.

25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph