WIAS Preprint No. 1720, (2012)

Elastic scattering by finitely many point-like obstacles



Authors

  • Hu, Guanghui
  • Sini, Mourad

2010 Mathematics Subject Classification

  • 74B05 78A45 81Q10

Keywords

  • linear elasticity, point-like scatterers, Navier equation, Green's tensor, far field pattern

Abstract

This paper is concerned with the time-harmonic elastic scattering by a finite number $N$ of point-like obstacles in $R^n (n=2,3)$. We analyze the $N$-point interactions model in elasticity and derive the associated Green's tensor (integral kernel) in terms of the point positions and the scattering coefficients attached to them, following the approach in quantum mechanics for modeling $N$-particle interactions. In particular, explicit expressions are given for the scattered near and far fields corresponding to elastic plane waves or point-source incidences. As a result, we rigorously justify the Foldy method for modeling the multiple scattering by finitely many point-like obstacles for the Lame model. The arguments are based on the Fourier analysis and the Weinstein-Aronszajn inversion formula of the resolvent for the finite rank perturbations of closed operators in Hilbert spaces.

Appeared in

  • J. Math. Phys., 54 (2013) pp. 042901--16.

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