Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Perfectly matched layer for second-order time-domain elastic wave
  equation: formulation and stability   A time domain system of equations is proposed to model elastic wave
propagation in an unbounded two-dimensional anisotropic solid using perfectly
matched layer (PML). Starting from a system of first-order frequency domain
stress-velocity equations and using complex coordinate stretching approach with
a two-parameter stretch function, a second-order formulation is obtained. The
final system, which consists of just two second order equations along with four
auxiliary equations, is smaller than existing formulations, thereby simplifying
the problem and reducing the computational cost. The discrete stability of the
solutions for a given mesh size is examined with the help of a plane-wave
analysis of the corresponding continuous problem. It is shown that increasing
the scaling parameter of the stretch function leads to significant stability
improvements for certain anisotropic media that have known issues. Numerical
computations for different isotropic and anisotropic media are used to
illustrate the results.

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The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con