Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Singularities generated by the triple interaction of semilinear conormal
  waves   We study the local propagation of conormal singularities for solutions of
semilinear wave equations $\square u = P(y, u)$, where $P(y, u)$ is a
polynomial of degree $N \geq 3$ in $u$ with $C^\infty(\mathbb{R}^3_y)$
coefficients. We know from the work of Melrose & Ritter and Bony that if u is
conormal to three waves which intersect transversally at point $q$, then after
the triple interaction $u(y)$ is a conormal distribution with respect to the
three waves and the characteristic cone $Q$ with vertex at $q$. We compute the
principal symbol of $u$ at the cone and away from the hypersurfaces. We show
that if $\partial_u^3 P (q, u(q)) \neq 0$, $u$ is an ellipitic conormal
distribution.

32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ