Results 11 to 20 of about 927,050 (285)
Spectral Singularities with Directional Sensitivity [PDF]
Physical Review A, 2021 We propose a class of spectral singularities that are sensitive to the direction of excitation and arise in nonlinear systems with broken parity symmetry.
Ramezani, Hamidreza
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Universal twinkling exponents for spectral fluctuations associated with mixed chaology [PDF]
, 2000 For systems that are neither fully integrable nor fully chaotic, bifurcations of periodic orbits give rise to semiclassically emergent singularities in the fluctuating part Nfl of the energy-level counting function. The bifurcations dominate the spectral
Keating, J. P. +2 more
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A note on the polynomial approximation of vertex singularities in the boundary element method in three dimensions [PDF]
, 2008 We study polynomial approximations of vertex singularities of the type $r^\lambda |\log r|^\beta$ on three-dimensional surfaces. The analysis focuses on the case when $\lambda > -\frac 12$.
Bespalov, A
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Indefinite Hamiltonian systems whose Titchmarsh–Weyl coefficients have no finite generalized poles of non-positive type [PDF]
, 2013 The two-dimensional Hamiltonian system (*) y'(x)=zJH(x)y(x), x∈(a,b), where the Hamiltonian H takes non-negative 2x2-matrices as values, and $J:= \begin{pmatrix} 0 & -1 \\ 1 & 0 \end{pmatrix}$, has attracted a lot of interest over the past decades ...
Harald Woracek +3 more
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Universal form of arrays with spectral singularities [PDF]
Optics Letters, 2020 An array of non-Hermitian optical waveguides can operate as a laser or as a coherent perfect absorber, which corresponds to a spectral singularity of the underlying discrete complex potential. We show that all lattice potentials with spectral singularities are characterized by the universal form of the gain-and-loss distribution.
Dmitry A. Zezyulin, Vladimir V. Konotop
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Cavity-controlled spectral singularity [PDF]
Optics Letters, 2014 We study theoretically a PT-symmetric saturable balanced gain-loss system in a ring cavity configuration. The saturable gain and loss are modeled by two-level medium with or without population inversion. We show that the specifics of the spectral singularity can be fully controlled by the cavity and the atomic detuning parameters.
Reddy, K. Nireekshan, Gupta, S. Dutta
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Spectral Properties on a Circle with a Singularity [PDF]
Journal of the Physical Society of Japan, 2003 TeX, 26 pages.
Fülöp, Tamás +2 more
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A function space model for canonical systems [PDF]
, 2011 Recently, a generalization to the Pontryagin space setting of the notion of canonical (Hamiltonian) systems which involves a finite number of inner singularities has been given.
Woracek, H., Langer, Matthias
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On the spectral singularities and spectrality of the Hill operator [PDF]
Operators and Matrices, 2016 First we study the spectral singularity at infinity and investigate the connections of the spectral singularities and the spectrality of the Hill operator. Then we consider the spectral expansion when there is not the spectral singularity at infinity.
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AR models of singular spectral matrices [PDF]
Proceedings of the 48h IEEE Conference on Decision and Control (CDC) held jointly with 2009 28th Chinese Control Conference, 2009 This paper deals with autoregressive models of singular spectra. The starting point is the assumption that there is available a transfer function matrix W(q) expressible in the form D−1(q)B for some tall constant matrix B of full column rank and with the determinantal zeros of D(q) all stable.
Brian D. O. Anderson +3 more
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