Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optimal dispersive estimates for the wave equation with $C^{(n-3)/2}$
  potentials in dimensions $4\le n\le 7$   We prove optimal dispersive estimates for the wave group
$e^{it\sqrt{-\Delta+V}}$ for a class of real-valued potentials $V\in
C^{(n-3)/2}({\bf R}^n)$, $4\le n\le 7$, such that $\partial_x^\alpha
V(x)=O(|x|^{-\delta})$ for $|x|>1$, where $\delta>(n+1)/2$.

35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat