Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Smoothed quantum-classical states in time-irreversible hybrid dynamics   We consider a quantum system continuously monitored in time which in turn is
coupled to an arbitrary dissipative classical system (diagonal reduced density
matrix). The quantum and classical dynamics can modify each other, being
described by an arbitrary time-irreversible hybrid Lindblad equation. Given a
measurement trajectory, a conditional bipartite stochastic state can be
inferred by taking into account all previous recording information (filtering).
Here, we demonstrate that the joint quantum-classical state can also be
inferred by taking into account both past and future measurement results
(smoothing). The smoothed hybrid state is estimated without involving
information from unobserved measurement channels. Its average over recording
realizations recovers the joint time-irreversible behavior. As an application
we consider a fluorescent system monitored by an inefficient photon detector.
This feature is taken into account through a fictitious classical two-level
system. The average purity of the smoothed quantum state increases over that of
the (mixed) state obtained from the standard quantum jump approach.

10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con