Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Global well-posedness for the Benjamin equation in low regularity   In this paper we consider the initial value problem of the Benjamin equation
$$ \partial_{t}u+\nu \H(\partial^2_xu)
  +\mu\partial_{x}^{3}u+\partial_xu^2=0, $$ where $u:\R\times [0,T]\mapsto \R$,
and the constants $\nu,\mu\in \R,\mu\neq0$. We use the I-method to show that it
is globally well-posed in Sobolev spaces $H^s(\R)$ for $s>-3/4$. Moreover, we
use some argument to obtain a good estimative for the lifetime of the local
solution, and employ some multiplier decomposition argument to construct the
almost conserved quantities.

31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
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The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
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The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
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The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph