Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Cauchy Problem for properly hyperbolic equations in one space
  variable   In this paper we consider the Cauchy problem for higher order weakly
hyperbolic equations. We assume that the principal symbol depends only on one
space variable and the characteristic roots $\tau_j$ verify the inequality
\[\tau_j^2(x) + \tau_k^2(x) \le M \bigl(\tau_j(x)-\tau_k(x)\bigr)^2\] for some
constant $M$ independent of $x$. We prove that if the lower order terms verify
a suitable Levi condition, the Cauchy problem is well-posed in
$\mathcal{C}$-infinity.

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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: stat
0
The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph
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The categories of this paper are: nlin
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The categories of this paper are: nucl-th
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The categories of this paper are: physics
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: cs