Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A simple theory for the Raman spike   The classical stimulated Raman scattering system describing resonant
interaction between two electromagnetic waves and a fast relaxing medium wave
is studied by introducting a systematic perturbation approach in powers of the
relaxation time. We separate amplitude and phase effects for these complex
fields. The analysis of the former shows the existence of a stagnation distance
after which monotonous energy transfer begins from one electromagnetic wave to
the other and this quantity is calculated. Concerning phase effects we give the
conditions for the formation of a Raman spike from an initial fast and large
phase jump in one of the waves. The spike evolution and width estimated from
the reduced model agree with the results from numerical simulations of the
original system.

31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph