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We develop a theory to compute and interpret the photonic band structure of a periodic array of metallic helices for the first time. Interesting features of band structure include the ingenuous longitudinal and circularly polarized…

Optics · Physics 2010-12-13 Chao Wu , Hongqiang Li , Zeyong Wei , Xiaotong Yu , C. T. Chan

The existence of a fundamental length (or fundamental time) has been conjectured in many contexts. However, the "stability of physical theories principle" seems to be the one that provides, through the tools of algebraic deformation theory,…

High Energy Physics - Theory · Physics 2011-11-24 R. Vilela Mendes

In this paper, we expand the theory of depth-unbiased source localization to unbiased parameter estimation and signal reconstruction of an arbitrary number of non-zero parameters to be recovered. The topic touches on the concept of exact…

Information Theory · Computer Science 2026-05-08 Joonas Lahtinen

This work concerns generalized backward stochastic differential equations, which are coupled with a family of reflecting diffusion processes. First of all, we establish the large deviation principle for forward stochastic differential…

Probability · Mathematics 2024-07-23 Yawen Liu , Huijie Qiao

We prove existence and uniqueness of a reaction-diffusion equation whose diffusivity is a non-linear functional of the boundary temperature. We do this by studying systems of one-dimensional reflecting diffusions whose noise is a function…

Probability · Mathematics 2021-07-29 Clayton Barnes

Recent advances in twistor theory are applied to geometric optics in ${\Bbb{R}}^3$. The general formulae for reflection of a wavefront in a surface are derived and in three special cases explicit descriptions are provided: when the…

Differential Geometry · Mathematics 2021-11-15 Brendan Guilfoyle , Wilhelm Klingenberg

The existence of a fundamental length (or fundamental time) has been conjectured in many contexts. However, the "stability of physical theories principle" seems to be the one that provides, through the tools of algebraic deformation theory,…

High Energy Physics - Theory · Physics 2015-06-03 R. Vilela Mendes

We present a new method for analyzing the global stability of the Sedov-von Neumann-Taylor self-similar solutions, describing the asymptotic behavior of spherical decelerating shock waves, expanding into ideal gas with density \propto…

Astrophysics · Physics 2009-11-10 Doron Kushnir , Eli Waxman , Dov Shvarts

We show that dispersive shock waves resulting from the nonlinearity overbalancing a weak leading-order dispersion can emit resonant radiation owing to higher-order dispersive contributions. We analyze such phenomenon for the defocusing…

Pattern Formation and Solitons · Physics 2015-06-17 Matteo Conforti , Fabio Baronio , Stefano Trillo

A new condition for the linear dissipative instability of the strong plane shock wave in an arbitrary medium is obtained. The instability of the shock is realized due to the flow instability behind its front, which is similar to the known…

Fluid Dynamics · Physics 2020-06-24 Sergey G. Chefranov

Here we investigate the accuracy of the overlap criterion when applied to a simple near-integrable model in both its 2D and 3D version. To this end, we consider respectively, two and three quartic oscillators as the unperturbed system, and…

Chaotic Dynamics · Physics 2009-11-13 M. F. Mestre , P. M. Cincotta , C. M. Giordano

This paper addresses the inverse problem of simultaneously recovering multiple unknown parameters for semilinear wave equations from boundary measurements. We consider an initial-boundary value problem for a wave equation with a general…

Analysis of PDEs · Mathematics 2026-05-28 Dong Qiu , Xiang Xu , Yeqiong Ye , Ting Zhou

Linear stability of supersonic flow over a short compression corner with ramp angles 30 and 42 is investigated using Direct Simulation Monte Carlo (DSMC) and Linear Stability Theory (LST) at Mach number 3, Reynolds number 11,200 and low…

Fluid Dynamics · Physics 2024-05-14 Irmak T. Karpuzcu , Vassilis Theofilis , Deborah A. Levin

The most general linear and local set of boundary conditions, involving relations between the normal components of the D and B vectors and tangential components of the E and H vectors at each point of the boundary, are considered in this…

Classical Physics · Physics 2017-02-17 I. V. Lindell , A. Sihvola

Supersonic flow is a typical nonlinear, nonequilibrium, multiscale, and complex phenomenon. This paper applies discrete Boltzmann method/model (DBM) to simulate and analyze these characteristics. A Burnett-level DBM for supersonic flow is…

Fluid Dynamics · Physics 2025-02-19 Yanbiao Gan , Zhaowen Zhuang , Bin Yang , Aiguo Xu , Dejia Zhang , Feng Chen , Jiahui Song , Yanhong Wu

This paper concerns the dynamic stability of the steady 3-D wave structure of a planar normal shock front intersecting perpendicularly to a planar solid wall for unsteady potential flows. The stability problem can be formulated as a free…

Analysis of PDEs · Mathematics 2021-08-23 Beixiang Fang , Feimin Huang , Wei Xiang , Feng Xiao

We use multi-spacecraft Magnetospheric Multiscale (MMS) observations to investigate electric fields and ion reflection at a non-stationary collisionless perpendicular plasma shock. We identify sub-proton scale (5-10 electron inertial…

Space Physics · Physics 2024-11-20 Yuri V. Khotyaintsev , Daniel B. Graham , Andreas Johlander

The stationary background flow in the spherically symmetric infall of a compressible fluid, coupled to the space-time defined by the static Schwarzschild metric, has been subjected to linearized perturbations. The perturbative procedure is…

Astrophysics · Physics 2008-12-18 Tapan Naskar , Nabajit Chakravarty , Jayanta K. Bhattacharjee , Arnab K. Ray

The probability that a particle, crossing the shock along a given direction, be reflected backwards along another direction, was shown to be the key element in determining the spectrum of non--thermal particles accelerated via the Fermi…

Astrophysics · Physics 2009-11-10 Pasquale Blasi , Mario Vietri

Two frameworks that have been used to characterize reflected diffusions include stochastic differential equations with reflection and the so-called submartingale problem. We introduce a general formulation of the submartingale problem for…

Probability · Mathematics 2014-12-03 Weining Kang , Kavita Ramanan