arXiv subjects

Michael Ibison

Publications and source records attributed to Michael Ibison.

7 recordsLinked to original sources

arXiv2011

The Dirac Field at the Future Conformal Singularity

We examine in detail the effect of the conformal factor associated with the Friedmann-Robertson-Walker spacetimes on the discrete symmetries usually present in the Dirac theory and analyze the behavior of the Dirac wavefunction near the future conformal singularity. We find that only two of the 4 bi-spinor components survive to the boundary, one effect of which is to cause the geodesics to experience a drag towards the Hubble frame. We then present arguments for the existence of a genuine boundary condition on the wavefunction at the future conformal singularity based upon the assumption there is no redundant copy of the universe in the post-conformal singularity era. This future boundary condition affects the spectral decomposition of the wavefunction, and this maybe locally testable at the present time.

physics.gen-ph↗

arXiv2010

Electrodynamics with a Future Conformal Horizon

We investigate the impact of singularities occurring at future times in solutions of the Friedmann equations expressed in conformal coordinates. We focus on the consequences of extending the time coordinate through the singularity for the physics of matter and radiation occupying just one side. Mostly this involves investigation of the relationship between the metric with line element ds^2 = a^2(t) * (dt^2 - dx^2) and time reversal symmetry within electrodynamics. It turns out compatibility between these two is possible only if there is a singular physical event at the time of the singularity or if the topology is not trivial. In both cases the singularity takes on the appearance of a time-like mirror. We are able to demonstrate a relationship between the broken time symmetry in electrodynamics characterized by retarded radiation and radiation reaction and the absolute conformal time relative to the time of the singularity, i.e. between the Electromagnetic and Cosmological arrows of time. It is determined that the Wheeler-Feynman reasoning but with the future absorber replaced by the Cosmological mirror leads to a conflict with observation unless matter is electromagnetically strongly bound to the environment.

physics.gen-ph↗

arXiv2004

Massless classical electrodynamics

In the direct action form of classical EM we give the equation of motion for a classical massless bare charge without self-interaction in the presence of an external field. That equation permits superluminal speeds and time-reversals, and so is a realization of the Stueckelberg-Feynman view of electrons and positrons as different segments of a single trajectory. We give a particular solution to a one body problem, and briefly discuss some aspects of the two-body problem. There is some discussion of the historical context of this effort, including the direct action and absorber theories, and some speculation on how the massless bare charge may acquire mass, and how these findings impact the problem of singular self-action.

physics.gen-ph↗

arXiv2004

Investigation of the polarizable vacuum cosmology

The basic cosmological predictions of a `polarizable-vacuum' theory of gravity due to Dicke, predating the scalar-tensor theory, are investigated and tested for their compliance with current observations. A Friedmann-like equation is derived for the theory that differs in a significant way from that of GR, for which it is demonstrated that a big bang is not a solution: the initial scale factor may be small but not zero, and must have zero first derivative. Detailed graphs of the predictions of the theory for combinations of the density parameters are given. It is shown that these predictions are compatible with current estimates for the age and deceleration parameter, and the maximum observable redshift, provided the matter density $Ω_m$ is close to the luminous matter density, i.e. provided there is not a significant amount of missing mass. For these best fit parameters, the theory predicts a maximum initial temperature that is too small for BBN and probably too small to support an era of radiation domination. The theory predicts a radiation power from a binary system that is 2/3 that predicted by GR, and so incompatible with observed orbital decay rate of PSR 1913 + 16. There is some discussion of possible developments, including reconciliation through accommodation of vacuum anisotropy, and of the relation between PV and the Yilmaz theory and the quasi-steady-state cosmology.

astro-ph↗

arXiv2003

Electrodynamics in the zero-point field: on the equilibrium spectral energy distribution and the origin of inertial mass

Attempts at an electromagnetic explanation of the inertial mass of charged particles have recently been revived within the framework of Stochastic Electrodynamics, characterized by the adoption of a classical version of the electromagnetic zero-point field (ZPF). Recent claims of progress in that area have to some extent received support from related claims that the classical equilibrium spectrum of charged matter is that of the classically conceived ZPF. The purpose of this note is to suggest that some strong qualifications should accompany these claims. It is pointed out that a classical massless charge cannot acquire mass from nothing as a result of immersion in any EM field, and therefore that the ZPF alone cannot provide a full explanation of inertial mass. Of greater concern, it is observed that the peculiar circumstances under which classical matter is in equilibrium with the ZPF do not concur with observation.

physics.gen-ph↗

arXiv2003

Relativistic integro-differential form of the Lorentz-Dirac equation in 3D without runaways

It is well known that the third-order Lorentz-Dirac equation admits runaway solutions wherein the energy of the particle grows without limit, even when there is no external force. These solutions can be denied simply on physical grounds, and on the basis of careful analysis of the correspondence between classical and quantum theory. Nonetheless, one would prefer an equation that did not admit unphysical behavior at the outset. Such an equation - an integro-differential version of the Lorentz-Dirac equation - is currently available either in 1 dimension only, or in 3 dimensions only in the non-relativistic limit. It is shown herein how the Lorentz-Dirac equation may be integrated without approximation, and is thereby converted to a second-order integro-differential equation in 3D satisfying the above requirement. I.E., as a result, no additional constraints on the solutions are required because runaway solutions are intrinsically absent. The derivation is placed within the historical context established by standard works on classical electrodynamics by Rohrlich, and by Jackson.

physics.gen-ph↗

arXiv1999

The speed of gravity revisited

Recently Van Flandern concluded from astrophysical data that gravity propagates faster than light. We demonstrate that the data can be explained by current theory that does not permit superluminal speeds. We explain the origin of apparently instantaneous connections, first within EM, and then within strong-field GR.

physics.gen-ph↗