480 research outputs found
Yilmaz Theory of SNe 1a Redshift
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
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
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?
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
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
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?
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
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?
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?
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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