Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Second-order Stark effect and polarizability of a relativistic
  two-dimensional hydrogen-like atom in the ground state   The second-order Stark effect for a planar Dirac one-electron atom in the
ground state is analyzed within the framework of the Rayleigh-Schr\"odinger
perturbation theory, with the use of the Sturmian series expansion of the
generalized Dirac-Coulomb Green function. A closed-form analytical expression
for the static dipole polarizability of that system is found. The formula
involves a generalized hypergeometric function ${}_{3}F_{2}$ with the unit
argument. Numerical values of the polarizabilities for relativistic planar
hydrogenic atoms with atomic numbers $1\leqslant Z\leqslant68$ are provided in
a tabular form. A simple formula for the polarizability of a nonrelativistic
two-dimensional hydrogenic atom, reported previously by several other authors,
is recovered from our result in the nonrelativistic limit.

36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom