Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Perturbation Theory for Singular Potentials in Quantum Mechanics   We study perturbation theory in certain quantum mechanics problems in which
the perturbing potential diverges at some points, even though the energy
eigenvalues are smooth functions of the coefficient of the potential. We
discuss some of the unusual techniques which are required to obtain
perturbative expansions of the energies in such cases. These include a
point-splitting prescription for expansions around the Dirichlet (fermionic)
limit of the $\delta$-function potential, and performing a similarity
transformation to a non-Hermitian potential in the Calogero-Sutherland model.
As an application of the first technique, we study the ground state of the
$\delta$-function Bose gas near the fermionic limit.

12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an