Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low frequency analogue Hawking radiation: The Korteweg-de Vries model   We derive analytic expressions for the low-frequency properties of the
analogue Hawking radiation in a general weak-dispersive medium. A thermal
low-frequency part of the spectrum is expected even when dispersive effects
become significant. We consider the two most common class of weak-dispersive
media and investigate all possible anomalous scattering processes due
inhomogeneous background flows. We first argue that under minimal assumptions,
the scattering processes in near-critical flows are well described by a
linearized Korteweg-de Vries equation. Within our theoretical model greybody
factors are neglected, that is, the mode co-moving with the flow decouples from
the other ones. We also exhibit a flow example with an exact expression for the
effective temperature. We see that this temperature coincides with the Hawking
one only when the dispersive length scale is much smaller than the flow
gradient scale. We apply the same method in inhomogeneous flows without an
analogue horizon. In this case, the spectrum coefficients decrease with
decreasing frequencies. Our findings are in agreement with previous numerical
works, generalizing their findings to arbitrary flow profiles. Our analytical
expressions provide estimates to guide ongoing experimental efforts.

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The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin
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The categories of this paper are: math
29
The categories of this paper are: funct-an
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The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
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The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: quant-ph