Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Absorbing boundary conditions for dynamical many-body quantum systems   In numerical studies of the dynamics of unbound quantum mechanical systems,
absorbing boundary conditions are frequently applied. Although this certainly
provides a useful tool in facilitating the description of the system, its
applications to systems consisting of more than one particle is problematic.
This is due to the fact that all information about the system is lost upon
absorption of one particle; a formalism based solely on the Scrh{\"o}dinger
equation is not able to describe the remainder of the system as particles are
lost. Here we demonstrate how the dynamics of a quantum system with a given
number of identical fermions may be described in a manner which allows for
particle loss. A consistent formalism which incorporates the evolution of
sub-systems with a reduced number of particles is constructed through the
Lindblad equation. Specifically, the transition from an $N$-particle system to
an $(N-1)$-particle system due to a complex absorbing potential is achieved by
relating the Lindblad operators to annihilation operators. The method allows
for a straight forward interpretation of how many constituent particles have
left the system after interaction. We illustrate the formalism using
one-dimensional two-particle model problems.

31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex