arXiv subjects

Reva Kay Williams

Publications and source records attributed to Reva Kay Williams.

7 recordsLinked to original sources

arXiv2018

Could Dark Energy be a Manifestation of Gravity?

It is shown that so-called dark energy could possible be a manifestation of the gravitational vortex producing the "gravitomagnetic" (GM) force field: associated with cosmic matter rotation and inertial spacetime frame dragging. The general relativistic Godel-Obukhov spacetime metric which incorporates expansion and rotation of the Universe is used to evaluate this force. This metric is expressed here in spherical comoving coordinates. Through a cosmic time evolution, it is shown that cosmic acceleration is expected when the magnitude of the radial repulsive GM force exceeds that of the familiar or usual attractive gravitational "gravitoelectric" (GE) force: associated with just cosmic matter and spacetime warping (or curvature). In general, this phenomenon of cosmic accelerated expansion appears to have occurred twice in the history of the Universe: the inflationary phase and the present-day acceleration phase. It is suggested in this model that the two phases may or may not be related. The cosmological model presented here is described in the context of Einstein's Theory of General Relativity in Riemann-Cartan spacetime (the "generalized" Einstein- Cartan theory of gravity), which includes cosmic rotation, its effect of spacetime torsion, and it being considered as an intrinsic part of gravity. Also, an associated derived analytical expression for the cosmic primordial magnetic field is presented. Evolving this magnetic field over cosmic time shows it to be consistent with theory and observations. In addition, it appears that the spin density of cosmic matter couples this magnetic field to the GM field, and also couples this magnetic field to the GE field.

physics.gen-ph↗

arXiv2004

Collimated Escaping Vortical Polar e-e+ Jets Intrinsically Produced by Rotating Black Holes and Penrose Processes

In this paper, I present results from theoretical and numerical (Monte Carlo) N-particle fully relativistic 4-D analysis of Penrose scattering processes (Compton and gamma-gamma-->e-e+) in the ergosphere of a supermassive or stellar mass Kerr (rotating) black hole. Specifically, the escape conditions and the escaping orbits of the Penrose pair production (gamma-gamma-->e-e+) electrons are analyzed, revealing that these particles escape along collimated, jet geodesic trajectories encircling the polar axis. Such collimated vortical tightly wound coil-like trajectories of relativistic particles are inherent properties of rotating black holes. The helical polar angles of escape for these e-e+ pairs range from 40 degrees to 0.5 degree (for the highest energy particles). These jet distributions appear to be consistent with the astrophysical jets of active galactic nuclei (AGNs) and galactic black holes and suggest a mechanism for precollimation within the inner radius of the dynamically stable accretion disk.

astro-ph↗

arXiv2004

New Energy Source Controlled by Gravity Alone?

I present a theoretical and numerical (Monte Carlo) N-particle analysis of Penrose scattering processes in the ergosphere of a supermassive Kerr black hole. These GR model calculations reveal that the observed high energies and luminosities of quasars and other active galactic nuclei, the collimated jets about the polar axis, and the asymmetrical jets (which can be enhanced by relativistic Doppler beaming effects) all are inherent properties of rotating black holes. The Penrose scattered escaping relativistic particles exhibit tightly wound coil-like cone distributions (highly collimated vortical jet distributions) about the polar axis, with helical polar angles of escape varying from 0.5-30 deg for the highest energy particles. The gravitomagnetic field exerts a force acting on the momentum vectors of the incident and scattered particles, causing asymmetrical particle jet emission above and below the equatorial plane. When the accretion disk is assumed to be an ADAF, energies as high as 54 GeV can be attained by these Penrose processes alone; and when relativistic beaming is included, energies in the TeV range can be achieved, agreeing with observations of some BL Lac objects. This energy-momentum extraction model can be applied to any size black hole. When this model is applied specifically to quasars 3C 279, 3C 273, Seyfert 1 galaxy MCG--60-30-15, and galactic black hole source Cygnus X-1, their observed high energy luminosity spectra in general can be explained. The consistency of these Penrose model calculations with observations suggests that the external magnetic field of the accretion disk plays a negligible role in the extraction of energy-momentum from a rotating black hole, close to the event horizon, where gravitational forces appear to be dominant.

astro-ph↗

arXiv2004

A Word from a Black Female Relativistic Astrophysicist: Setting the Record Straight on Black Holes

This Letter is written to clear up a situation, and hopefully we will learn something from it: scientifically and morally. Herein is presented a true ``historical'' scenario of events, that led to my being the first person (Williams 1991) to successfully work out the Penrose mechanism in four-dimensions (three-space momenta and energy). Before working out a solution to the Penrose mechanism: to extract energy from a rotating black hole, the Penrose mechanism (since first proposed by Roger Penrose in 1969) had been attempted by scientists over the world for nearly two decades, with little success, although making some progress. In the Penrose analysis of Williams (1991, 1995) details of the behavior of efficient Penrose relativistic scattering processes in the ergosphere are described. The reason a solution eluded other scientists before me is that there was very little known about orbits inside the ergosphere, where space and time are no longer separable, as measured by an observer at infinity (i.e., far away from the Kerr black hole). In this Letter, I describe how analytic derivations of the conserved energy and azimuthal angular momentum of particle orbits not confined to the equatorial plane allowed me to succeed where others, whose ``shoulders'' I stood on, had failed. Also, I will mention some well known scientists in the astrophysics community by name, as I discuss their involvement, and outline the facts behind an author feeling the need to set the record straight.

physics.soc-ph↗

arXiv2004

The Gravitomagnetic Field and Penrose Processes

Results from general relativistic theoretical Monte Carlo computer simulations of Compton scattering and e-e+ pair production processes in the ergosphere of a supermassive (10^8 solar mass) rotating black hole are presented. Particles from an accretion disk fall into the ergosphere and scatter off particles that are in bound equatorially and nonequatorially confined orbits. The Penrose mechanism, in general, allows rotational energy of a Kerr black hole to be extracted by scattered particles escaping from the ergosphere to infinity (i.e., large distances from the black hole). The results of these model calculations show that a form of the Penrose mechanism is capable of producing the observed high energy particles (up to of order GeV) emitted by quasars and other active galactic nuclei (AGNs), without the necessity of the external electromagnetic field of the accretion disk. Importantly, these model calculations show that the Lense-Thirring effect, i.e., the dragging of inertial frames into rotation, caused by the angular momentum of the rotating black hole, results in a gravitomagnetic (GM) force being exerted on the scattered escaping particles. Inside the ergosphere, where this dragging is severe, in appears that the GM vector field lines are frame dragged into the positive azimuthal direction, i.e., the direction of rotation of the black hole. The resulting GM force acting on the Penrose scattered particles produces symmetrical and asymmetrical (or one-sided) particle emissions in the polar direction, consistent with the astrophysical jets observed in radio strong AGNs. Note, these Penrose processes can apply to any size rotating black hole.

astro-ph↗

arXiv2003

Production of the High Energy-Momentum Spectra of Quasars 3C 279 and 3C 273 Using the Penrose Mechanism

Theoretical and numerical (Monte Carlo) N-particle computer model simulations show that Penrose Compton scattering (PCS) near the event horizon and Penrose pair production (PPP) at or near the photon orbit, in the ergosphere of a supermassive rotating black hole, can generate the necessary energy-momentum spectra to explain the origin of the mysterious fluxes of ultrarelativistic electrons, inferred from observations to emerge from the cores of Quasars 3C 279 and 3C 273, and other active galactic nuclei (AGNs). Particles from an accretion disk surrounding the black hole fall into the ergosphere and scatter off particles that are in trapped or bound unstable orbits. The Penrose mechanism allows rotational energy of a Kerr black hole, and energy-momentum produced by its strong gravitational field, to be extracted by scattered particles escaping from the ergosphere to infinity. The results of these model calculations show that the Penrose mechanism is capable of producing the observed high energy particles (~GeV) emitted by quasars and other AGNs. This mechanism can extract hard X-ray/gamma-ray photons from PCS of initially infalling low energy UV/soft X-ray photons by target orbiting electrons in the ergosphere. The PPP allows the escape of relativistic e-e+ pairs--produced by infalling low energy photons interacting with highly blueshifted target photons at the photon orbit. Moreover, and importantly, the emission of scattered particles by this mechanism naturally produces relativistic jets collimated about the polar axis, and in most cases one-sided or asymmetrical, agreeing with observations of AGNs. In these fully relativistic calculations, the energy-momentum four vectors (or four-momenta) of the scattered particles are obtained.(ABRIDGED)

astro-ph↗

arXiv2001

Collimated Energy-Momentum Extraction from Rotating Black Holes in Quasars and Microquasars Using the Penrose Mechanism

For almost four decades, since the discovery of quasars, mounting observational evidence has accumulated that black holes indeed exist in nature. In this paper, I present a theoretical and numerical (Monte Carlo) fully relativistic 4-D analysis of Penrose scattering processes (Compton at radii between the marginally stable, marginally bound orbits and gamma-gamma-->$e^-e^+$ pair production at the photon orbit) in the ergosphere of a supermassive Kerr (rotating) black hole. These model calculations surprisingly reveal that the observed high energies and luminosities of quasars and other active galactic nuclei (AGNs), the collimated jets about the polar axis, and the asymmetrical jets (which can be enhanced by relativistic Doppler beaming effects) all are inherent properties of rotating black holes. From this analysis, it is shown that the Penrose scattered escaping relativistic particles exhibit tightly wound coil-like cone distributions (highly collimated vortical jet distributions) about the polar axis, with helical polar angles of escape varying from $0.5^o$ to $30^o$ for the highest energy particles. It is also shown that the gravitomagnetic (GM) field, which causes the dragging of inertial frames, exerts a force acting on the momentum vectors of the incident and scattered particles, causing the particle emission to be asymmetrical above and below the equatorial plane, thus appearing to break the equatorial reflection symmetry of the Kerr metric. This energy-momentum extraction model can be applied to any size black hole, irrespective of the mass, and therefore applies to microquasars as well.

astro-ph↗