arXiv subjects
Publications and source records attributed to Borge Nodland.
We propose that spacetime is fundamentally a property of matter, inseparable from it. This leads us to suggest that all properties of matter must be elevated to the same status as that of spacetime in quantum field theories of matter. We suggest a specific method for extending field theories to accomodate this, and point out how this leads to the evolution of fields through channels other than the spacetime channel.
The propagation of an electromagnetic pulse in a plasma is studied for pulse durations that are comparable to the plasma period. When the carrier frequency of the incident pulse is much higher than the plasma frequency, the pulse propagates without distortion at its group speed. When the carrier frequency is comparable to the plasma frequency, the pulse is distorted and leaves behind it an electromagnetic wake.
We discuss a new mechanism which could cause a rotation of polarization of electromagnetic waves due to magnetic fields on cosmological scales. The effect is due to the geometrical phase of Pancharatnam and Berry, and causes a corkscrew twisting of the plane of polarization. The new effect represents an additional tool that allows possible intergalactic and cosmological magnetic fields to be studied using radio propagation.
We review evidence for a new phenomenon in the propagation of radio waves across the Universe, an anisotropic rotation of the plane of polarization not accounted for by conventional physics.
Recently, J. P. Leahy commented (astro-ph/9704285) on the indication of anisotropy in the propagation of radio waves over cosmological distances, published by Nodland and Ralston (B. Nodland and J. P. Ralston, Phys. Rev. Lett. 78, 3043 (1997); astro-ph/9704196). Unfortunately, Leahy ignores the need for a statistical comparison, egregiously selects data, compares incompatible measures, uses a variable incapable of resolving birefringence, and makes mistakes in the calculations he presents.
Eisenstein and Bunn have widely circulated a Comment (astro-ph/9704247) suggesting a non-standard null hypothesis in a test for cosmological birefringence. The Comment misrepresents the procedure used by Nodland and Ralston (B. Nodland and J. P. Ralston, Phys. Rev. Lett. 78, 3043 (1997); astro-ph/9704196) and lacks statistical basis; no calculations were reported, but sweeping conclusions were drawn from eyeballing a single scatter plot. The results of the suggested procedure range from an underestimate of the statistical significance of well-correlated data, to a failure of detecting a perfect correlation in the limit of strong cuts. We verified these faults by performing the actual calculation which EB suggested, but neglected to carry out themselves. Furthermore, the calculation showed that the original correlation remains statistically significant, with the lego-plot of 1/P versus s showing a persistent bump, and the anisotropy direction s remaining in the same direction as previously reported.
We present evidence for a new phenomenon in the propagation of electromagnetic radiation across the Universe, a corkscrew rotation of the plane of polarization not accounted for by conventional physics.
We apply expansion methods to obtain an approximate expression in terms of elementary functions for the space and time dependence of wave packets in a dispersive medium. The specific application to pulses in a cold plasma is considered in detail, and the explicit analytic formula that results is provided. When certain general initial conditions are satisfied, these expressions describe the packet evolution quite well. We conclude by employing the method to exhibit aspects of dispersive pulse propagation in a cold plasma, and suggest how predicted and experimental effects may be compared to improve the theoretical description of a medium's dispersive properties.
We report a systematic rotation of the plane of polarization of electromagnetic radiation propagating over cosmological distances. The effect is extracted independently from Faraday rotation, and found to be correlated with the angular positions and distances to the sources. Monte Carlo analysis yields probabilistic P-values of order 10^(-3) for this to occur as a fluctuation. A fit yields a birefringence scale of order 10^(25) meters. Dependence on redshift z rules out a local effect. Barring hidden systematic bias in the data, the correlation indicates a new cosmological effect.