Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An electron of helium atom under a high-intensity laser field   We scrutinize the behavior of eigenvalues of an electron of Helium atom as it
interacts with electric field directed along $z$-axis and exposed to linearly
polarized intense laser field radiation. In order to achieve this, we freeze
one electron of the helium atom at its ionic ground state and the motion of the
second electron in the ion core is treated via a more general case of screened
Coulomb potential model. Using the Kramers-Henneberger (KH) unitary
transformation, which is semiclassical counterpart of the Block-Nordsieck
transformation in the quantized field formalism, the squared vector potential
that appears in the equation of motion is eliminated and the resultant equation
is expressed in KH frame. Within this frame, the resulting potential and the
corresponding wave function have been expanded in Fourier series and using
Ehlotzkys approximation, we obtain a laser-dressed potential to simulate
intense laser field. By fitting the more general case of screened Coulomb
potential model into the laser-dressed potential, and then expanding it in
Taylor series up to $\mathcal{O}(r^4,\alpha_0^9)$, we obtain the solution
(eigenvalues and wave function) of an electron of Helium atom under the
influence of external electric field and high-intensity laser field, within the
framework of perturbation theory formalism. We found that the variation in
frequency of laser radiation has no effect on the eigenvalues of an electron of
helium for a particular electric field intensity directed along $z$-axis. Also,
for a very strong external electric field and an infinitesimal screening
parameter, the system is strongly bound. This work has potential application in
the areas of atomic and molecular processes in external fields including
interactions with strong fields and short pulses.

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The categories of this paper are: cmp-lg
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The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
1
The categories of this paper are: cs
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
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The categories of this paper are: q-fin
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The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga