Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Finite time blowup of solutions to semilinear wave equation in an
  exterior domain   We consider the initial-boundary value problem of semilinear wave equation
with nonlinearity $|u|^p$ in exterior domain in $\mathbf{R}^N$ $(N\geq 3)$.
Especially, the lifespan of blowup solutions with small initial data are
studied. The result gives upper bounds of lifespan which is essentially the
same as the Cauchy problem in $\mathbf{R}^N$. At least in the case $N=4$, their
estimates are sharp in view of the work by Zha--Zhou (2015). The idea of the
proof is to use special solutions to linear wave equation with Dirichlet
boundary condition which are constructed via an argument based on
Wakasa--Yordanov.

27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int