Note to the paper by R. Hempel, A. M. Hinz, and H. Kalf: On the essential spectrum of Schr�dinger operators with spherically symmetric potentials

1987 ◽  
Vol 277 (2) ◽  
pp. 209-211 ◽  
Author(s):  
J. Weidmann
1987 ◽  
Vol 277 (2) ◽  
pp. 197-208 ◽  
Author(s):  
Rainer Hempel ◽  
Andreas M. Hinz ◽  
Hubert Kalf

Author(s):  
Mahir Hadžić ◽  
Gerhard Rein ◽  
Christopher Straub

AbstractWe consider two classes of steady states of the three-dimensional, gravitational Vlasov-Poisson system: the spherically symmetric Antonov-stable steady states (including the polytropes and the King model) and their plane symmetric analogues. We completely describe the essential spectrum of the self-adjoint operator governing the linearized dynamics in the neighborhood of these steady states. We also show that for the steady states under consideration, there exists a gap in the spectrum. We then use a version of the Birman-Schwinger principle first used by Mathur to derive a general criterion for the existence of an eigenvalue inside the first gap of the essential spectrum, which corresponds to linear oscillations about the steady state. It follows in particular that no linear Landau damping can occur in the neighborhood of steady states satisfying our criterion. Verification of this criterion requires a good understanding of the so-called period function associated with each steady state. In the plane symmetric case we verify the criterion rigorously, while in the spherically symmetric case we do so under a natural monotonicity assumption for the associated period function. Our results explain the pulsating behavior triggered by perturbing such steady states, which has been observed numerically.


2020 ◽  
Vol 2020 (2) ◽  
pp. 44-51
Author(s):  
E.B. Dilmurodov

Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan

This chapter presents the basics of the ‘effective-one-body’ approach to the two-body problem in general relativity. It also shows that the 2PN equations of motion can be mapped. This can be done by means of an appropriate canonical transformation, to a geodesic motion in a static, spherically symmetric spacetime, thus considerably simplifying the dynamics. Then, including the 2.5PN radiation reaction force in the (resummed) equations of motion, this chapter provides the waveform during the inspiral, merger, and ringdown phases of the coalescence of two non-spinning black holes into a final Kerr black hole. The chapter also comments on the current developments of this approach, which is instrumental in building the libraries of waveform templates that are needed to analyze the data collected by the current gravitational wave detectors.


Sign in / Sign up

Export Citation Format

Share Document