Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mobile impurity in a Bose-Einstein condensate and the orthogonality
  catastrophe   We analyze the properties of an impurity in a dilute Bose-Einstein condensate
(BEC). First the quasiparticle residue of a static impurity in an ideal BEC is
shown to vanish with increasing particle number as a stretched exponential,
leading to a bosonic orthogonality catastrophe. Then we introduce a variational
ansatz, which recovers this exact result and describes the macroscopic dressing
of the impurity including its back-action onto the BEC as well as boson-boson
repulsion beyond the Bogoliubov approximation. This ansatz predicts that the
orthogonality catastrophe also occurs for mobile impurities, whenever the BEC
becomes ideal. Finally, we show that our ansatz agrees well with experimental
results.

29
The categories of this paper are: funct-an
2
The categories of this paper are: math
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat