Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gaussian impurity moving through a Bose-Einstein superfluid   In this paper a Gaussian impurity moving through an equilibrium Bose-Einstein
condensate at T = 0 is studied. The problem can be described by a
Gross-Pitaevskii equation, which is solved perturbatively. The analysis is done
for systems of 2 and 3 spatial dimensions and generalises the work by [G.E.
Astrakharchik and L.P. Pitaevskii, Phys. Rev. A 70, 013608 (2004)]. The
Bogoliubov equation solutions for the condensate perturbed by a finite impurity
are calculated in the co-moving frame, which are formally equivalent up to a
dimension dependent form factor for general dimensions. From those solutions
the total energy of the perturbed system is determined as a function of the
width and the amplitude of the moving Gaussian impurity and its velocity.
Finally we derive the drag force the Gaussian impurity approximately
experiences as it moves through the superfluid, which proofs the existence of a
superfluid phase for finite extensions of the impurities below the speed of
sound and that the force increases monotonically with velocity until it
decreases again.

26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph