Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Exponential localization of hydrogen-like atoms in relativistic quantum
  electrodynamics   We consider two different models of a hydrogenic atom in a quantized
electromagnetic field that treat the electron relativistically. The first one
is a no-pair model in the free picture, the second one is given by the
semi-relativistic Pauli-Fierz Hamiltonian. We prove that the no-pair operator
is semi-bounded below and that its spectral subspaces corresponding to energies
below the ionization threshold are exponentially localized. Both results hold
true, for arbitrary values of the fine-structure constant, $e^2$, and the
ultra-violet cut-off, $\Lambda$, and for all nuclear charges less than the
critical charge without radiation field, $Z_c=e^{-2}2/(2/\pi+\pi/2)$. We obtain
similar results for the semi-relativistic Pauli-Fierz operator, again for all
values of $e^2$ and $\Lambda$ and for nuclear charges less than $e^{-2}2/\pi$.

32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn