Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Diffraction of particles in free fall   The problem of a beam of quantum particles falling through a diffractive
screen is studied. The solutions for single and double slits are obtained
explicitly when the potential is approximated by a linear function. It is found
that the resulting patterns depend on a quasi-time $\tau$ given by a function
of the coordinate along the propagation axis in a classical combination
$z_0-t^2 F/m$, while the diffraction effects along transverse axes are due
solely to $m/\hbar$. The consequences on the precision at which the equivalence
principle can be tested are discussed. Realizations with ultra cold neutrons,
Bose-Einstein condensates and molecular beams are proposed.

18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg