Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Note on Decay Rates of the Local Energy for Wave Equations with
  Lipschitz Wavespeeds   We consider the Cauchy problem for wave equations with variable coefficients
in the whole space. We improve the rate of decay of the local energy, which has
been recently studied by J. Shapiro, where he derives the log-order decay rates
of the local energy under stronger assumptions on the regularity of the initial
data.

1
The categories of this paper are: cs
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an