Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Continuously induced coherence without induced emission   The coherence properties of two downconversion processes continuously coupled
via idler beams are analyzed. We find that the amount of which-way information
about a signal photon carried by idler beams periodically attains its maximum
and minimum in the course of evolution. In correspondence with the famous
experiments by Mandel's group on the induced coherence without induced emission
the coherence of signal beams is governed by that information. The ideal
which-way measurement is constructed.

23
The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
2
The categories of this paper are: math
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The categories of this paper are: nucl-th
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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph