Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Equivalence of the effective Hamiltonian approach and the Siegert
  boundary condition for resonant states   Two theoretical methods of finding resonant states in open quantum systems,
namely the approach of the Siegert boundary condition and the Feshbach
formalism, are reviewed and shown to be algebraically equivalent to each other
for a simple model of the T-type quantum dot. It is stressed that the seemingly
Hermitian Hamiltonian of an open quantum system is implicitly non-Hermitian
outside the Hilbert space. The two theoretical approaches extract an explicitly
non-Hermitian effective Hamiltonian in a contracted space out of the seemingly
Hermitian (but implicitly non-Hermitian) full Hamiltonian in the
infinite-dimensional state space of an open quantum system.

7
The categories of this paper are: hep-th
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn