464 research outputs found

    Yilmaz Theory of SNe 1a Redshift

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    A redshift-luminosity distance relation in excellent agreement with observations is calculated here for SNe 1a using the Yilmaz gravitational theory. In contrast to the current conventional explanation based on general relativity, the Yilmaz theory does not require a cosmological constant term that implies the existence of "dark energy". The Yilmaz theory requires only one parameter; a mean mass-energy density of the cosmos. The required value is essentially the same as the critical density for a Friedmann-Robertson-Walker cosmological metric. The Yilmaz theory therefore still requires the existence of non-baryonic dark matter.Comment: 13 pages, 1 figur

    A Gedanken Experiment For Gravitomagnetism

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    A gedanken experiment implies the existence of gravitomagnetism and raises a question about what we know about the weak-field limit of the gravitomagnetic field of General Relativity.Comment: 6 page

    The Intrinsic Magnetic Fields of the Galactic Black Hole Candidates

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    Recent work has linked the quiescent luminosities and hard/soft spectral state switches of neutron stars (NSs) to their spinning magnetic fields. It is shown here that the quiescent luminosities and spectral switches of galactic black hole candidates (BHCs) could be produced in the same way for spin rates below 100 Hz and magnetic fields above 10^10 G. It is also shown that the ultrasoft peaks and large flickering amplitudes of the BHCs would be expected from the surfaces of massive NSs. None of the few spectral characteristics that distinguish BHCs from low mass NSs have been explained in terms of event horizons. Serious consideration of the possibility that they might simply be massive NSs opens an avenue for proof of event horizons by negation, but requires the use of a space-time metric that has no event horizon. The Yilmaz exponential metric used here is shown to have an innermost marginally stable orbit with radius, binding energy and Keplerian frequency that are within a few percent of the same quantities for the Schwarzschild metric. A maximum NS mass of ~10 solar mass is found for the Yilmaz metric. The two metrics essentially differ only by the presence/absence of a surface for the BHCs, thus enabling proof or disproof of the existence of an event horizon.Comment: 34 pages, 4 figures, aas2pp4.st

    Do Black Holes Exist?

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    Proof that black holes exist will likely require confirmation of the existence of event horizons. The common assumption that the mere existence of large compact masses proves the case for black holes is an unwarranted extrapolation of General Relativity into a strong-field regime where it has not been adequately tested. Neither the large compact masses of galactic nuclei nor the massive compact objects of stellar mass in the x-ray binaries prove the existence of black holes. In contrast to the case for galactic nuclei, we have the necessary tools for obtaining either proof or disproof of event horizons in the x-ray binaries. Observations of kHz QPOs may decide the event horizon issue very quickly. If not, we can still obtain proof by comparing predictions of gravity theories that differ primarily by the presence or absence of an event horizon. Detailed analysis of models of x-ray binaries would then decide the issue.Comment: [email protected] - Submitted to PAS

    MECO In An Exponential Metric

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    Magnetic Eternally Collapsing Objects (MECO) have been proposed as the central engines of galactic black hole candidates (GBHC) and supermassive active galactic nuclei (AGN). Previous work has shown that their luminosities and spectral and timing characteristics are in good agreement with observations. These features and the formation of jets are generated primarily by the interactions of accretion disks with an intrinsically magnetic central MECO. The interaction of accretion disks with the anchored magnetic fields of the central objects permits a unified description of properties for GBHC, AGN, neutron stars in low mass x-ray binaries and dwarf novae systems. The previously published MECO models have been based on a quasistatic Schwarzschild metric of General Relativity; however, the only essential feature of this metric is its ability to produce extreme gravitational redshifts. For reasons discussed in this article, an alternative development based on a quasistatic exponential metric is considered here.Comment: 24 pages. This revision changes the MECO model for consistency with an exponential metric. It is similar to arXiv:astro-ph/0602453, but differing in details associated with differences between the Schwarzschild and exponential metrics. It also corrects typos and other minor errors associated with V1 of this submissio

    Newtonian Gravity Predictions For Gravity Probe B

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    Newtonian gravity and special relativity combine to produce a gravitomagnetic precession of an orbiting gyroscope that is one fourth as large as predicted by General Relativity. The geodetic effect is the same in both cases.Comment: 9 pages. Mathematical error correcte

    Does Sgr A* Have an Intrinsic Magnetic Moment Instead of an Event Horizon?

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    In previous work we have developed a general relativistic, magnetospheric eternally collapsing object (MECO) model for black hole candidates and shown that the model is consistent with broad band spectral and luminosity characteristics and accounts for the radio/x-ray luminosity correlations of both galactic black hole candidates (GBHC) and active galactic nuclei (AGN). We show here that the MECO model can: a) satisfy the luminosity constraints that have been claimed as proof of an event horizon for Sgr A*, b) reconcile the low bolometric luminosity with the expected Bondi accretion rate for Sgr A* by means of a magnetic propeller driven outflow, c) account for the Sgr A* NIR and x-ray luminosities, the general characteristics of its broad band spectrum, and the sequence of flares in different spectral ranges as well as the pattern of its observed orthogonal polarizations. We also include specific predictions for images that may be obtained in sub-millimeter to NIR wavelengths in the near future. Additional future tests for the presence of an intrinsic magnetic moment for Sgr A* will require global solutions for electron density and magnetic field distributions in a Bondi accretion flow into a compact, rotating magnetic dipole. These will provide for definitive tests in the form of detailed calculations of spectral and spatial luminosity distributions and polarization maps for direct comparison with high resolution images of Sgr A*.Comment: Updated to include luminosity calculations and predictions for images that may be observed in the future. 30 page

    The Magnetospheric Eternally Collapsing Object (MECO) Model of Galactic Black Hole Candidates and Active Galactic Nuclei

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    The spectral, timing, and jet formation properties of neutron stars in low mass x-ray binary systems are influenced by the presence of central magnetic moments. Similar features shown by the galactic black hole candidates (GBHC) strongly suggest that their compact cores might be intrinsically magnetic as well. We show that the existence of intrinsically magnetic GBHC is consistent with a new class of solutions of the Einstein field equations of General Relativity. These solutions are based on a strict adherence to the Strong Principle of Equivalence (SPOE) requirement that the world lines of physical matter must remain timelike in all regions of spacetime. The new solutions emerge when the structure and radiation transfer properties of the energy momentum tensor on the right hand side of the Einstein field equations are appropriately chosen to dynamically enforce this SPOE requirement of timelike world line completeness. In this context, we find that the Einstein field equations allow the existence of highly red shifted, Magnetospheric, Eternally Collapsing Objects (MECO). MECO necessarily possess intrinsic magnetic moments and they do not have trapped surfaces that lead to event horizons and curvature singularities. Their most striking features are equipartition magnetic fields, pair plasma atmospheres and extreme gravitational redshifts. Since MECO lifetimes are orders of magnitude greater than a Hubble time, they provide an elegant and unified framework for understanding a broad range of observations of GBHC and active galactic nuclei. We examine their spectral, timing and jet formation properties and discuss characteristics that might lead to their confirmation.Comment: Synopsis of three previously published papers plus new results., 48 page

    Do Black Hole Candidates Have Magnetic Moments Instead of Event Horizons?

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    In previous work we found that many of the spectral properties of low mass x-ray binaries (LMXB), including galactic black hole candiates (GBHC) were consistent with the existence of intrinsically magnetized central objects. We review and extend these findings and show that the existence of intrisically magnetic BHC is consistent with a new class of solutions of the Einstein field equations of General Relativity. These solutions are based on a strict adherence to the Strong Principle of Equivalence (SPOE) requirement that the world lines of physical matter must remain timelike in all regions of spacetime. The new solutions emerge when the structure and radiation transfer properties of the energy momentum tensor on the right hand side of the Einstein field equations are appropriately chosen to dynamically enforce the SPOE requirement of timelike world line completeness. In this context, we find that the Einstein field equations allow the existence of highly red shifted, Magnetospheric, Eternally Collapsing Objects (MECO). MECO can possess intrinsic magnetic moments since they do not have trapped surfaces that lead to event horizons and curvature singularities. Since MECO lifetimes are orders of magnitude greater than a Hubble time, they provide an elegant and unified framework for understanding a broad range of observations of GBHC and active galactic nuclei. We examine their properties and discuss characteristics that might lead to their confirmation.Comment: 16 pages, 1 figure, new version has minor corrections and updated reference

    How Black Are Black Hole Candidates?

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    In previous work we found that many of the spectral properties of x-ray binaries, including both galactic black hole candiates (GBHC) and neutron stars, were consistent with the existence of intrinsically magnetized central objects. Here we review and extend the observational evidence for the existence of intrinsically magnetized GBHC and show that their existence is consistent with a new class of solutions of the Einstein field equations of General Relativity. These solutions are based on a strict adherence to the Principle of Equivalence, which prevents the time-like geodesics of physical matter from becoming null on trapped surfaces of infinite red shift. The new solutions emerge from the fact that the structure and radiation transfer properties of the energy-momentum tensor on the right hand side of the Einstein field equations must have a form that is consistent with this Principle of Equivalence requirement. In this context, we show that the Einstein field equations allow the existence of highly red shifted, magnetospheric, eternally collapsing objects (MECO) which do not have trapped surfaces which lead to event horizons. Since MECO lifetimes are many orders of magnitude greater than a Hubble time, they provide an elegant and unified framework for understanding the broad range of observations associated with GBHC and active galactic nuclei.Comment: 17 pages, submitted to Astrophysical Journa
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