Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Propagation of singularities for generalized solutions to nonlinear wave
  equations   The paper is devoted to regularity theory of generalized solutions to
semilinear wave equations with a small nonlinearity. The setting is the one of
Colombeau algebras of generalized functions. It is shown that in one space
dimension, an initial singularity at the origin propagates along the
characteristic lines emanating from the origin, as in the linear case. The
proof relies on a fixed point theorem in the ultra-metric topology on the
algebras involved. The paper takes up the initiating research of the 1970s on
anomalous singularities in classical solutions to semilinear hyperbolic
equations and transplants the methods into the Colombeau setting.

33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an