Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Boundary interactions changing operators and dynamical correlations in
  quantum impurity problems   Recent developments have made possible the computation of equilibrium
dynamical correlators in quantum impurity problems. In many situations however,
one is rather interested in correlators subject to a non equilibrium initial
preparation; this is the case for instance for the occupation probability
$P(t)$ in the double well problem of dissipative quantum mechanics (DQM). We
show in this paper how to handle this situation in the framework of integrable
quantum field theories by introducing ``boundary interactions changing
operators''. We determine the properties of these operators by using an
axiomatic approach similar in spirit to what is done for form-factors. This
allows us to obtain new exact results for $P(t)$; for instance, we find that
that at large times (or small $g$), the leading behaviour for $g < 1/2}$ is
$P(t)\propto e^{-\Gamma t}\cos\Omega t$, with the universal ratio.
$\Omega/\Gamma = \cot {\pi g}/{2(1-g)}$.

19
The categories of this paper are: eess
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg