Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Design techniques for superposition of acoustic bandgaps using fractal
  geometries   Research into properties of heterogeneous artificial materials, consisting of
arrangements of rigid scatterers embedded in a medium with different elastic
properties, has been intense throughout last two decades. The capability to
prevent the transmission of waves in predetermined bands of frequencies -called
bandgaps- becomes one of the most interesting properties of these systems, and
leads to the possibility of designing devices to control wave propagation. The
underlying physical mechanism is destructive Bragg interference. Here we show a
technique that enables the creation of a wide bandgap in these materials, based
on fractal geometries. We have focused our work in the acoustic case where
these materials are called Phononic/Sonic Crystals (SC) but, the technique
could be applied any types of crystals and wave types in ranges of frequencies
where the physics of the process is linear.

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The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
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The categories of this paper are: astro-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: adap-org
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The categories of this paper are: stat
10
The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc