Radiation-reaction-induced evolution of circular orbits of particles around Kerr Black Holes

It is demonstrated that, in the adiabatic approximation, non-Equatorial circular orbits of particles in the Kerr metric (i.e. orbits of constant Boyer-Lindquist radius) remain circular under the influence of gravitational radiation reaction. A brief discussion is given of conditions for breakdown of adiabaticity and of whether slightly non-circular orbits are stable against the growth of eccentricity.Comment: 23 pages. Revtex 3.0. Inquiries to [email protected]

Optomechanical cooling in a continuous system

Radiation-pressure-induced optomechanical coupling permits exquisite control of micro- and mesoscopic mechanical oscillators. This ability to manipulate and even damp mechanical motion with light---a process known as dynamical backaction cooling---has become the basis for a range of novel phenomena within the burgeoning field of cavity optomechanics, spanning from dissipation engineering to quantum state preparation. As this field moves toward more complex systems and dynamics, there has been growing interest in the prospect of cooling traveling-wave phonons in continuous optomechanical waveguides. Here, we demonstrate optomechanical cooling in a continuous system for the first time. By leveraging the dispersive symmetry breaking produced by inter-modal Brillouin scattering, we achieve continuous mode optomechanical cooling in an extended 2.3-cm silicon waveguide, reducing the temperature of a band of traveling-wave phonons by more than 30 K from room temperature. This work reveals that optomechanical cooling is possible in macroscopic linear waveguide systems without an optical cavity or discrete acoustic modes. Moreover, through an intriguing type of wavevector-resolved phonon spectroscopy, we show that this system permits optomechanical control over continuously accessible groups of phonons and produces a new form of nonreciprocal reservoir engineering. Beyond this study, this work represents a first step towards a range of novel classical and quantum traveling-wave operations in continuous optomechanical systems.Comment: Manuscript with supplementary information. 17 pages, 4 Figures. Minor correction in Fig.

System analysis approach to deriving design criteria (loads) for Space Shuttle and its payloads. Volume 1: General statement of approach

Space shuttle, the most complex transportation system designed to date, illustrates the requirement for an analysis approach that considers all major disciplines simultaneously. Its unique cross coupling and high sensitivity to aerodynamic uncertainties and high performance requirements dictated a less conservative approach than those taken in programs. Analyses performed for the space shuttle and certain payloads, Space Telescope and Spacelab, are used a examples. These illustrate the requirements for system analysis approaches and criteria, including dynamic modeling requirements, test requirements control requirements and the resulting design verification approaches. A survey of the problem, potential approaches available as solutions, implications for future systems, and projected technology development areas are addressed

System analysis approach to deriving design criteria (Loads) for Space Shuttle and its payloads. Volume 2: Typical examples

The achievement of an optimized design from the system standpoint under the low cost, high risk constraints of the present day environment was analyzed. Space Shuttle illustrates the requirement for an analysis approach that considers all major disciplines (coupling between structures control, propulsion, thermal, aeroelastic, and performance), simultaneously. The Space Shuttle and certain payloads, Space Telescope and Spacelab, are examined. The requirements for system analysis approaches and criteria, including dynamic modeling requirements, test requirements, control requirements, and the resulting design verification approaches are illustrated. A survey of the problem, potential approaches available as solutions, implications for future systems, and projected technology development areas are addressed

Templates for stellar mass black holes falling into supermassive black holes

The spin modulated gravitational wave signals, which we shall call smirches, emitted by stellar mass black holes tumbling and inspiralling into massive black holes have extremely complicated shapes. Tracking these signals with the aid of pattern matching techniques, such as Wiener filtering, is likely to be computationally an impossible exercise. In this article we propose using a mixture of optimal and non-optimal methods to create a search hierarchy to ease the computational burden. Furthermore, by employing the method of principal components (also known as singular value decomposition) we explicitly demonstrate that the effective dimensionality of the search parameter space of smirches is likely to be just three or four, much smaller than what has hitherto been thought to be about nine or ten. This result, based on a limited study of the parameter space, should be confirmed by a more exhaustive study over the parameter space as well as Monte-Carlo simulations to test the predictions made in this paper.Comment: 12 pages, 4 Tables, 4th LISA symposium, submitted to CQ