Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Remarks on Nonlinear Elastic Waves in the Radial Symmetry in 2-D   In this manuscript we first give the explicit variational structure of the
nonlinear elastic waves for isotropic, homogeneous, hyperelastic materials in
2-D. Based on this variational structure, we suggest a null condition which is
a kind of structural condition on the nonlinearity in order to stop the
formation of finite time singularities of local smooth solutions. In the radial
symmetric case, inspired by Alinhac's work [3] on 2-D quasilinear wave
equations, we show that such null condition can ensure the globalexistence of
smooth solutions with small initial data.

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The categories of this paper are: chao-dyn
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The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: astro-ph
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The categories of this paper are: solv-int
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The categories of this paper are: stat
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The categories of this paper are: adap-org
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The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-th
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The categories of this paper are: hep-ph
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The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
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The categories of this paper are: econ
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The categories of this paper are: nlin
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The categories of this paper are: hep-ex
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The categories of this paper are: eess