Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Master equation for high-precision spectroscopy   The progress in high-precision spectroscopy requires one to verify the
accuracy of theoretical models such as the master equation describing
spontaneous emission of atoms. For this purpose, we apply the coarse-graining
method to derive a master equation of an atom interacting with the modes of the
electromagnetic field. This master equation naturally includes terms due to
quantum interference in the decay channels and fulfills the requirements of the
Lindblad theorem without the need of phenomenological assumptions. We then
consider the spectroscopy of the 2S-4P line of atomic Hydrogen and show that
these interference terms, typically neglected, significantly contribute to the
photon count signal. These results can be important in understanding
spectroscopic measurements performed in recent experiments for testing the
validity of quantum electrodynamics.

36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys