English
Related papers

Related papers: Computation of Spiral Spectra

200 papers

Conditionspectrum measures the computational stability of solving a linear system. In this paper, ten theorems involving {\epsilon}-conditionspectrum are presented. All these theorems generalize a well known eigenvalue theorem and…

Spectral Theory · Mathematics 2011-09-14 Sukumar Daniel

We determine the spectrum of particles accelerated at shocks with arbitrary speed and arbitrary scattering properties for different choices of the equation of state of the downstream plasma. More specifically we consider the effect of…

Astrophysics · Physics 2009-11-13 G. Morlino , P. Blasi , M. Vietri

We study stability of monostable waves for reaction-diffusion systems. When the solution is initially close to a fast wave profile in optimal topology, we prove convergence to a shifted profile. The proof relies on explicit resolvent…

Analysis of PDEs · Mathematics 2026-02-27 Louis Garénaux

We compute the spectra of the adjacency matrices of the semi-regular polytopes. A few different techniques are employed: the most sophisticated, which relates the 1-skeleton of the polytope to a Cayley graph, is based on methods akin to…

Combinatorics · Mathematics 2007-05-23 Nicolau C. Saldanha , Carlos Tomei

We derive a simple, accurate, non-linear, global equation governing spiral density waves in thin, non-self-gravitating, inviscid accretion discs. These discs may have any slowly varying surface density or temperature profile. For specific…

Earth and Planetary Astrophysics · Physics 2025-12-15 Joshua J. Brown , Gordon I. Ogilvie

The limit distribution of the discrete spectrum of the Sturm-Liouville problem with complex-valued polynomial potential on an interval, on a half-axis, and on the entire axis is studied. It is shown that at large parameter values, the…

Spectral Theory · Mathematics 2016-04-20 A. A. Shkalikov , S. N. Tumanov

Spirals shocks have been widely studied in the context of galactic dynamics and protostellar discs. They may however also play an important role in some classes of close binary stars, and more particularly in cataclysmic variables. In this…

Astrophysics · Physics 2007-05-23 Henri M. J. Boffin

We introduce a simple, general, and convergent scheme to compute generalized eigenfunctions of self-adjoint operators with continuous spectra on rigged Hilbert spaces. Our approach does not require prior knowledge about the eigenfunctions,…

Numerical Analysis · Mathematics 2024-10-14 Matthew J. Colbrook , Andrew Horning , Tianyiwa Xie

An algorithm for computing eigenvalues and eigenfunctions of the angular spheroidal wave equation, based on a known but scarcely used method, is developed. By requiring the regularity of the wave function, represented by its series…

Classical Analysis and ODEs · Mathematics 2016-06-02 J. Sesma

Using the diagrammatic method, we derive a set of self-consistent equations that describe eigenvalue distributions of large correlated asymmetric random matrices. The matrix elements can have different variances and be correlated with each…

Disordered Systems and Neural Networks · Physics 2016-12-21 Alexander Kuczala , Tatyana O. Sharpee

The main subject of this paper is a computer assisted stability proof for a stationary solution of reaction diffusion equations in one dimensional space. We use Nakao's numerical verification method to enclose a stationary solution of…

Numerical Analysis · Mathematics 2015-01-20 Shuting Cai , Jing Zeng

We present a numerical method for computing the pure-point spectrum associated with the linear stability of multi-dimensional travelling fronts to parabolic nonlinear systems. Our method is based on the Evans function shooting approach.…

Dynamical Systems · Mathematics 2009-03-17 Veerle Ledoux , Simon J. A. Malham , Jitse Niesen , Vera Thümmler

Gaseous rotating razor-thin discs are a testing ground for theories of spiral structure that try to explain appearance and diversity of disc galaxy patterns. These patterns are believed to arise spontaneously under the action of…

Astrophysics of Galaxies · Physics 2017-12-11 E. V. Polyachenko

Spectral measures arise in numerous applications such as quantum mechanics, signal processing, resonances, and fluid stability. Similarly, spectral decompositions (pure point, absolutely continuous and singular continuous) often…

Spectral Theory · Mathematics 2021-03-02 Matthew John Colbrook

We consider planar traveling fronts between stable steady states in two-component singularly perturbed reaction-diffusion-advection equations, where a small quantity $\delta^2$ represents the ratio of diffusion coefficients. The fronts…

Analysis of PDEs · Mathematics 2023-10-24 Paul Carter

In this work an activator-depleted reaction-diffusion system is investigated on polar coordinates with the aim of exploring the relationship and the corresponding influence of domain size on the types of possible diffusion-driven…

Dynamical Systems · Mathematics 2018-01-11 Wakil Sarfaraz , Anotida Madzvamuse

The winding problem concerns understanding the regularity of functions which map a line segment onto a spiral. This problem has relevance in fluid dynamics and conformal welding theory, where spirals arise naturally. Here we interpret…

Classical Analysis and ODEs · Mathematics 2021-07-07 Jonathan M. Fraser

Structure and spectral energy distributions (SEDs) of externally irradiated circumstellar disks are often computed on the basis of the two-temperature model of Chiang & Goldreich. We refine these calculations by using a more realistic…

Astrophysics · Physics 2009-11-11 Roman R. Rafikov , Fabio De Colle

We consider steady surface waves in an infinitely deep two--dimensional ideal fluid with potential flow, focusing on high-amplitude waves near the steepest wave with a 120 degree corner at the crest. The stability of these solutions with…

Fluid Dynamics · Physics 2024-04-25 Bernard Deconinck , Sergey A. Dyachenko , Anastassiya Semenova

Spiral wave patterns observed in models of cardiac arrhythmias and chemical oscillations develop alternans and stationary line defects, which can both be thought of as period-doubling instabilities. These instabilities are observed on…

Dynamical Systems · Mathematics 2019-05-30 Stephanie Dodson , Bjorn Sandstede