Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The point source inverse back-scattering problem   We consider the inverse problem of recovering a potential by measuring the
response at a point to a source located at the same point and then varying the
point on the surface of a sphere. This is a similar to the inverse
back-scattering problem. We show that if the angular derivatives of the
difference of two potentials having the same data is controlled by the L^2 norm
of the difference of the potentials they must be equal. In particular this
shows injectivity of the inverse problem for radial potentials.

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The categories of this paper are: patt-sol
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
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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: ao-sci
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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
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The categories of this paper are: dg-ga
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The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg
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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: plasm-ph