Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universality of the dynamic characteristic relationship of electron
  correlation in the two-photon double ionization process of a helium-like
  system   Universality of the dynamic characteristic relationship between the
characteristic time $t_c$ and the two-electron Coulomb interaction energy
$\overline{V}_{12}$ of the ground state in the two-photon double ionization
process is investigated through changing the parameters of the two-electron
atomic system and the corresponding laser conditions. The numerical results
show that the product $t_{c}\overline{V}_{12}$ keeps constant around 4.1 in the
cases of changing the nucleus charge, the electron charge, the electron mass,
and changing simultaneously the nucleus charge and the electron charge. These
results demonstrate that the dynamic characteristic relationship in the
two-photon double ionization process is universal. This work sheds more light
on the the dynamic characteristic relationship in ultrafast processes and may
find its application in the measurement of attosecond pulses.

26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con