Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Total reflection of two guided waves for embedded trapped modes   To investigate the mechanism of wave trapping, acoustic embedded trapped
modes associated with two-resonant-mode interference in two-dimensional
duct-cavity structures are calculated by the feedback-loop closure principle,
which allows us to analyse the travelling modes that construct the trapped
modes. The exact two coexisting resonant modes that underpin an embedded
trapped mode in a cavity open to two semi-infinite ducts are numerically
demonstrated. At the interface between the cavity segment and a duct, total
reflection can occur for a particular combination of two propagative guided
waves in the cavity. With a particular cavity length and a particular
frequency, total reflection also happens for the two reflected waves at the
opposite end of the cavity. In this way, the two coexisting standing waves
underpin a trapped mode. It is found that the two standing waves are not two
closed-cavity modes. Thus, this work presents a new understanding of such
embedded trapped modes as a product of total reflection of two guided waves at
the interface between two waveguides, rather than interference between two
eigenmodes of a closed cavity. For quasi-trapped modes, the Fano scattering
phenomenon owing to the effects of two acoustic channels is also shown.

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The categories of this paper are: hep-th
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The categories of this paper are: math
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The categories of this paper are: hep-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: nlin
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The categories of this paper are: hep-lat
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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: stat
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The categories of this paper are: cs
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The categories of this paper are: astro-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: adap-org