Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Decoherence in a fermion environment: Non-Markovianity and Orthogonality
  Catastrophe   We analyze the non-Markovian character of the dynamics of an open two-level
atom interacting with a gas of ultra-cold fermions. In particular, we discuss
the connection between the phenomena of orthogonality catastrophe and Fermi
edge singularity occurring in such a kind of environment and the memory-keeping
effects which are displayed in the time evolution of the open system.

17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
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The categories of this paper are: adap-org
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
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The categories of this paper are: solv-int
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The categories of this paper are: eess
4
The categories of this paper are: cond-mat
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The categories of this paper are: comp-gas
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-th
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The categories of this paper are: math-ph
30
The categories of this paper are: q-alg