Results 261 to 270 of about 927,050 (285)

Singular solitons and spectral meromorphy

Russian Mathematical Surveys, 2017
Let \(u\) be a real- or complex-valued function on \(\mathbb{R}\) with an isolated singularity at \(x_0\), \textit{J. J. Duistermaat} and \textit{F. A. Grünbaum} [Commun. Math. Phys. 103, 177--240 (1986; Zbl 0625.34007)] found a necessary and sufficient condition for \(u\) which ensures that for all \(E\) all solutions of \[ [-(d/dx)^2+ u]\psi= E\psi ...
Grinevich, Petr G., Novikov, Sergei P.
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Spectral Analysis of Singularities

1979
In Chapter VII we have seen that a distribution u of compact support is smooth if and only if the Fourier transform u is rapidly decreasing. If u is not smooth we can use the set of directions where u is not rapidly decreasing to describe which are the high frequency components of u causing the singularities.
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Spectral Theory in the Singular Case

1991
As was noted in Section 1 of Chapter 1, a Sturm-Liouville problem is said to be singular if either the interval [a, b] is infinite or if the function q(x) on [a, b] is not summable (or both). Here, we obtain the expansion theorem for the singular problem, considering it as the limit of regular ones.
B. M. Levitan, I. S. Sargsjan
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On the spectral singularities of the truncated shift

Acta Mathematica Hungarica, 1988
The first result of this paper is that, for truncated shift operators, S- spectrality and the spectrality in the sense of Vasyunin are equivalent. Then, by applying several results of Vasyunin, it is shown that the set of the spectral singularities \(S(T_ F)\) of the truncated shift operator \(T_ F\) contains the support of the singular continuous part
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The spectral rigidity of curve singularities

1994
Summary: We announce results on spectral asymptotics of algebraic curves, equipped with any metric which can be induced from a Hermitian metric on complex projective space, via some projective embedding. We prove that the \(\zeta\)-function of the Laplacian is meromorphic, and that the singularities of the curve can be detected from spectral ...
Brüning, Jochen, Lesch, Matthias
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Functional model and spectral singularities

1987
Translation from Probl. Mat. Fiz. 9, 113-121 (Russian) (1979; Zbl 0494.47013).
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Difference equations of second order with spectral singularities

Journal of Mathematical Analysis and Applications, 2003
Murat Adıvar, Elgiz Bayram
exaly  

Spectral analysis of the impulsive quadratic pencil of Schrödinger operators with spectral singularities

Complex Variables and Elliptic Equations, 2023
exaly  

Quadratic eigenparameter dependent discrete Sturm–Liouville equations with spectral singularities

Applied Mathematics and Computation, 2014
Nihal Yokus, Turhan Koprubasi
exaly  

Conjectures on Spectral Numbers for Upper Triangular Matrices and for Singularities

Mathematical Physics Analysis and Geometry, 2020
Claus Hertling
exaly