Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum electrodynamics in a laser and the electron laser collision   Quantum electrodynamics in a laser is formulated, in which the electron-laser
interaction is exactly considered, while the interaction of an electron and a
single photon is considered by perturbation. The formulation is applied to the
electron-laser collisions. The effect of coherence between photons in the laser
is therefore fully considered in these collisions. The possibility of
$\gamma-$ray laser generation by use of this kind of collision is discussed.

30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th