Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sonic metamaterials: reflection on the role of topology on dispersion
  surface morphology   Investigating dispersion surface morphology of sonic metamaterials is crucial
in providing information on related phenomena as inertial coupling, acoustic
transparency, polarisation, and absorption. In the present study, we look into
frequency surface morphology of two-dimensional metamaterials of K3,3 and K6
topologies. The elastic structures under consideration consist of the same
substratum lattice points and form a pair of sublattices with hexagonal
symmetry. We show that, through introducing universal localised mass-in-mass
phononic microstructures at lattice points, six single optical
frequency-surfaces can be formed with required properties including negative
group velocity. Splitting the frequency-surfaces is based on the classical
analog of the quantum phenomenon of "energy-level repulsion", which can be
achieved only through internal anisotropy of the nodes and allows us to obtain
different frequency band gaps.

13
The categories of this paper are: quant-ph
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The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th