A bstract We investigate the effect of superradiant scattering gravitational perturbations on stability rotating black strings, focusing six dimensional equal-spinning Myers-Perry string. find that rapidly strings are unstable to modes within a bounded range string lengths. The instability occurs because momentum along direction creates potential barrier allows for confinement modes. Yet, five ...

We consider the quasilinear Kirchhoff's problem$$ u_{tt}-phi (x)||nabla u(t)||^{2}Delta u+f(u)=0 ,;; x in {mathcal{R}}^{N}, ;; t geq 0,$$with the initial conditions  $ u(x,0) = u_0 (x)$  and $u_t(x,0) = u_1 (x)$, in the case where $N geq 3, ;  f(u)=|u|^{a}u$ and $(phi (x))^{-1} in L^{N/2}({mathcal{R}}^{N})cap L^{infty}({mathcal{R}}^{N} )$ is a positive function. The purpose of our work is to ...

This paper deals with the isogeometric analysis using B-splines of space rods subject to Kirchhoff-Love hypotheses. A multi-patch isogeometric approach for the numerical analysis of the three-dimensional Kirchhoff-Love rod theory is developed. We use Bezier and B-splines interpolations and we show that they are able to attain very good accuracy for rod structures, particularly for developing a ...

Kirchhoff diffraction formulations that use the wave front and the aperture plane for the surfaces of integration were compared. The full Kirchhoff obliquity factor terms distinguishing these two formulations are presented for spherical waves and for Gaussian laser beams. When they are used, identical results are obtained for the two formulations in both the spherical-wave and the Gaussian lase...

We present an experimental study of the angular distribution of light scattered from several rough metallic surfaces, which cover a range of roughness conditions. A BRDF model based on the Kirchhoff approximation was used to demonstrate the relation between surface-height statistics and the angular distribution of the scattered light. To do this, the angular distributions calculated with the BR...

Everyday experience shows that twisted elastic filaments spontaneously form loops. We model the dynamics of this looping process as a sequence of bifurcations of the solutions to the Kirchhoff equation describing the evolution of thin elastic filament. The control parameter is taken to be the initial twist density in a straight rod. The first bifurcation occurs when the twisted straight rod def...

The recent application of tomographic methods to three-dimensional imaging through tissue by use of light often requires modeling of geometrically complex diffuse-nondiffuse boundaries at the tissue-air interface. We have recently investigated analytical methods to model complex boundaries by means of the Kirchhoff approximation. We generalize this approach using an analytical approximation, th...