scholarly journals Does Levinson’s theorem count complex eigenvalues?

2017 ◽  
Vol 58 (10) ◽  
pp. 102101
Author(s):  
F. Nicoleau ◽  
D. Parra ◽  
S. Richard
Keyword(s):  
Levinson’S Theorem ◽  
Complex Eigenvalues

Eigenvalue Problem for the Second Order Differential Equation with Nonlocal

2006 ◽  
Vol 11 (1) ◽  
pp. 13-32 ◽  
Author(s):  
B. Bandyrskii ◽  
I. Lazurchak ◽  
V. Makarov ◽  
M. Sapagovas
Keyword(s):  
Differential Equation ◽  
Eigenvalue Problem ◽  
Variable Coefficient ◽  
Order Differential Equation ◽  
Integral Condition ◽  
Second Order ◽  
Computational Results ◽  
Discrete Method ◽  
Complex Eigenvalues ◽  
Nonlocal Integral Condition

The paper deals with numerical methods for eigenvalue problem for the second order ordinary differential operator with variable coefficient subject to nonlocal integral condition. FD-method (functional-discrete method) is derived and analyzed for calculating of eigenvalues, particulary complex eigenvalues. The convergence of FD-method is proved. Finally numerical procedures are suggested and computational results are schown.

Locating complex eigenvalues for analytical eddy-current models used to detect flaws

2019 ◽  
Vol 38 (6) ◽  
pp. 1800-1809
Author(s):  
Grzegorz Tytko ◽  
Łukasz Dawidowski
Keyword(s):  
Eddy Current ◽  
Design Methodology ◽  
Complex Function ◽  
Precise Determination ◽  
Argument Principle ◽  
Content Type ◽  
Conductive Material ◽  
Complex Roots ◽  
Complex Eigenvalues

Purpose Discrete eigenvalues occur in eddy current problems in which the solution domain was truncated on its edge. In case of conductive material with a hole, the eigenvalues are complex numbers. Their computation consists of finding complex roots of a complex function that satisfies the electromagnetic interface conditions. The purpose of this paper is to present a method of computing complex eigenvalues that are roots of such a function. Design/methodology/approach The proposed approach involves precise determination of regions in which the roots are found and applying sets of initial points, as well as the Cauchy argument principle to calculate them. Findings The elaborated algorithm was implemented in Matlab and the obtained results were verified using Newton’s method and the fsolve procedure. Both in the case of magnetic and nonmagnetic materials, such a solution was the only one that did not skip any of the eigenvalues, obtaining the results in the shortest time. Originality/value The paper presents a new effective method of locating complex eigenvalues for analytical solutions of eddy current problems containing a conductive material with a hole.

Weyl’s theory applied to predissociation by rotation. II. Determination of resonances and complex eigenvalues: Application to HgH

1976 ◽  
Vol 65 (11) ◽  
pp. 4571-4574 ◽  
Author(s):  
Michael Hehenberger ◽  
Piotr Froelich ◽  
Erkki Brändas
Keyword(s):  
Complex Eigenvalues

Three-alpha resonant state and its contribution in continuum spectrum

2006 ◽  
Vol 21 (31n33) ◽  
pp. 2351-2358
Author(s):  
C. Kurokawa ◽  
K. Katō
Keyword(s):  
Boundary Condition ◽  
Resonant State ◽  
Level Density ◽  
Complex Scaling ◽  
Scaling Method ◽  
Complex Scaling Method ◽  
Resonant States ◽  
Complex Eigenvalues ◽  
Three Body ◽  
The Continuum

The 3α resonant states of 12 C are investigated by taking into account the correct boundary condition for three-body resonant states. In order to show how the 3α resonant states having complex eigenvalues contribute to the real energy, we calculated the Continuum Level Density in the Complex Scaling Method.

Half-Bound States and Levinson’s Theorem for Discrete Systems

1991 ◽  
Vol 22 (3) ◽  
pp. 754-768 ◽  
Author(s):  
D. B. Hinton ◽  
M. Klaus ◽  
J. K. Shaw
Keyword(s):  
Bound States ◽  
Discrete Systems ◽  
Levinson’S Theorem
Sign in / Sign up

Export Citation Format

Share Document