Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 199 )

2018 ( 296 )

2017 ( 306 )

2016 ( 474 )

Custom range...

Search Results: 1 - 10 of 232681 matches for " Frank R. Tangherlini "
All listed articles are free for downloading (OA Articles)
Page 1 /232681
Display every page Item
Einstein’s Pseudo-Tensor in n Spatial Dimensions for Static Systems with Spherical Symmetry  [PDF]
Frank R. Tangherlini
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.49163

It was noted earlier that the general relativity field equations for static systems with spherical symmetry can be put into a linear form when the source energy density equals radial stress. These linear equations lead to a delta function energymomentum tensor for a point mass source for the Schwarzschild field that has vanishing self-stress, and whose integral therefore transforms properly under a Lorentz transformation, as though the particle is in the flat space-time of special relativity (SR). These findings were later extended to n spatial dimensions. Consistent with this SR-like result for the source tensor, Nordstrom and independently, Schrodinger, found for three spatial dimensions that the Einstein gravitational energy-momentum pseudo-tensor vanished in proper quasi-rectangular coordinates. The present work shows that this vanishing holds for the pseudo-tensor when extended to n spatial dimensions. Two additional consequences of this work are: 1) the dependency of the Einstein gravitational coupling constant κ on spatial dimensionality employed earlier is further justified; 2) the Tolman expression for the mass of a static, isolated system is generalized to take into account the dimensionality of space for n

Galilean-Like Transformation Allowed by General Covariance and Consistent with Special Relativity  [PDF]
Frank R. Tangherlini
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.55033

As shown earlier, a linear transformation with the same form for the spatial coordinates as the Lorentz transformation (LT), and that allows for time dilation, but leaves simultaneity invariant instead of the one-way speed of light, predicts the same results as the LT for the usual tests of special relativity. Such a transformation is allowed by general covariance. A complementarity between the invariance of the one-way speed of light and the invariance of simultaneity is discussed. Using this transformation, interpreted as involving external synchronization, it is shown that two frames moving uniformly with equal and opposite velocities, v and –v relative to a third inertial frame, in which clocks are synchronized so that the one-way speed of light is c, can be related by a Galilean-like transformation with a relative velocity 2v/(1-(v/c)2).These transformations do not form a group, hence the term “pseudo-Galilean” is used to distinguish them from the Galilean transformations. An analogy with the Sagnac effect is discussed, and consistency with the LT for stellar aberration, and the Doppler effect is shown. Implication of the above complementarity for the possible unification of quantum theory and gravitation is briefly discussed, as well as the inferred physical significance of general covariance.

A Possible Alternative to the Accelerating Universe  [PDF]
Frank R. Tangherlini
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.61010

A possible alternative to the accelerating universe is proposed, which shows that the diminished brightness of the high red shift Type Ia supernovae can be explained by assuming light travels with reduced speed through the dark energy of intergalactic space. It is also shown that support for the\"\"?model from baryon acoustic oscillations (BAO) studies can also be accommodated by the model. Two tables are given that compare the model with apparent magnitude differences and length differences between the\"\"?universe and the Einstein-de Sitter universe, and they show that the model yields these differences quite accurately. A third table comparing the apparent magnitude difference between\"\"?and a universe with \"\"is also given. It exhibits poor agreement with the model, and hence the model favors the need for dark energy, albeit without negative pressure. As a new approach to the “why now?” problem, and its apparent challenge to the Copernican principle, it is proposed that dark energy is a condensed form of dark matter caused by expansion cooling, rather than a different substance. A motivation for an alternative to\"\"?is presented based on a principle that rules out the cosmological term.

A Possible Alternative to the Accelerating Universe II  [PDF]
Frank R. Tangherlini
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.69141
Abstract: This work revises and extends the author’s previous work (2015), Journal of Modern Physics, 6, 78- 87, by proposing that the index of refraction n of intergalactic space (IGS) is of electromagnetic origin. This leads to a theoretical expression for n that agrees very well with the least squares value obtained previously. A table comparing the fractional distance increase predicted by the two differently obtained indices is given. This revised view requires that the high energy charged particles found in cosmic rays originate from high energy neutral particles, presumably high energy gamma rays, that were able to travel through the IGS without energy loss due to Cherenkov radiation. An alternative explanation for the counter indication from the IceCube findings of Abassi, R., et al. (2012) Nature, 484. 351-353 is proposed, which might also explain the findings of Aartsen et al. (2013) Physical Review Letters, 111, 021103. Since the model predicts galaxies act as divergent lenses, a geometrical analysis and corresponding figure describing this effect is given, as well as a table for a range of angles to the image galaxy relative to the direction to a target galaxy that is divergently lensed. The reduction of the speed of light in the IGS leads to a revision of the Planck (2015) value of the Hubble constant of ~68 km·s-1·Mpc-1 to ~47 km·s-1·Mpc-1, and hence an age for the Einstein-de Sitter universe greater than that of the oldest white dwarfs in the Galaxy, thereby resolving a long-standing problem with this model of the universe.
A Possible Alternative to the Accelerating Universe III  [PDF]
Frank R. Tangherlini
Journal of Modern Physics (JMP) , 2016, DOI: 10.4236/jmp.2016.713163
Abstract: This work extends the author’s two previous works (2015), Journal of Modern Physics, 6, 78-87, and 1360-1370, by obtaining the index of refraction n of the dark energy for additional values of the cosmological density parameters, and for the two methods of obtaining n: least squares fit, and electromagnetic theory. Comparison of the alternative model with the accelerating universe for the new values of the density parameters and n is given in two tables. The new values for n are used to obtain a range of ages for the Einstein de Sitter (EdS) universe. It is shown that the EdS universe must be older than the comparison accelerating universe. This requirement is met for the Planck 2015 value of the Hubble constant, corrected for the speed of light reduction by n. A supporting measurement as well as a disagreeing measurement is also discussed. Possible support from a stellar age determination is also discussed. It is shown that the expression obtained earlier for the increased apparent magnitude of the SNe Ia provides as good a fit for a closed universe with Ω(tot = 1.005) , as it does for the flat EdS universe. Comparison is presented in a third table. An upper bound on ΩΛ is given for a closed universe that eventually collapses back on itself that is too small for the value needed for the accelerating universe.
Speed of Gravitation and Electromagnetic Waves through the Dark Energy of Intergalactic Space and Its Implications of a Unified Theory  [PDF]
Frank R. Tangherlini
Journal of Modern Physics (JMP) , 2018, DOI: 10.4236/jmp.2018.94039
Abstract: The recent finding that gravitational waves (GW170817) traveled at the same speed as electromagnetic (EM) waves (GRB 170817A) from a binary neutron star merger does not necessarily mean that they traveled throughout their journey at speed c. Some recent works by the author (2015) Journal of Modern Physics, 6, 78-87, and 1360-1370; (2016), 7, 1829-1844; (2017), 8, 622-635 show that the diminished brightness of Type Ia supernovae (SNe Ia) can be explained by assuming that dark energy, instead of having a negative pressure, has an index of refraction n, causing the speed of light through intergalactic space (IGS) to be reduced to c/n, with? n1.5. It follows that GWs (not considered in the previous works) would also travel with speed c/n through IGS. However, speed of GWs and EMWs within galaxies themselves is c. A brief review of the model is given, together with other predictions, e.g., new values for the Hubble constant and age of the universe, and necessary absence of correlation of neutrinos with gamma ray bursts (GRBs), in agreement with numerous searches. In the previous works, there were implications of a unified theory. If the model holds, since GWs would experience the same speed reduction as EMWs, this would further support unification. An improved falsification methodology for a previously proposed astronomical test based on discordant redshifts is given.
A Possible Solution to the Disagreement about the Hubble Constant  [PDF]
Frank R. Tangherlini
Journal of Modern Physics (JMP) , 2018, DOI: 10.4236/jmp.2018.99116
Abstract: The current disagreement about the Hubble constant H0 was described as a “Crisis in Cosmology”, at the April (2018) Meeting of the American Physical Society, and hence its resolution is of utmost importance. This work proposes that the solution to the disagreement between the Planck Collaboration cosmic microwave background (CMB) value of H0, together with the very close BOSS Collaboration baryon acoustic oscillation (BAO) value, and the significantly higher value of H0 found by the SHOES Collaboration cosmic distance ladder (CDL) work, is due to the fact that the CMB and BAO values of H0 are not for an accelerating universe, as generally believed, but are actually the values for a decelerating universe. In contrast, the CDL value of H0 is indeed that for an accelerating universe. It is shown that by replacing the negative deceleration parameter in the expression for logH0 in the CDL work by a positive deceleration parameter, the value of H0 can be brought down to agree with the CMB and BAO lower values. There is a brief review of the author’s decelerating model based on the Einstein de Sitter universe, augmented by a model of dark energy that does not have a negative pressure, but instead has a non-dispersive index of refraction n, causing the speed of light through the dark energy of intergalactic space to be reduced to c/n. As reported earlier, this assumption is sufficient to accommodate the increase in apparent magnitude of the Type Ia supernovae (SNe Ia). Additional support for the model is presented, together with a proposal for astronomical falsification.
Semi-Supervised Morphosyntactic Classification of Old Icelandic
Kryztof Urban, Timothy R. Tangherlini, Aurelijus Vijūnas, Peter M. Broadwell
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0102366
Abstract: We present IceMorph, a semi-supervised morphosyntactic analyzer of Old Icelandic. In addition to machine-read corpora and dictionaries, it applies a small set of declension prototypes to map corpus words to dictionary entries. A web-based GUI allows expert users to modify and augment data through an online process. A machine learning module incorporates prototype data, edit-distance metrics, and expert feedback to continuously update part-of-speech and morphosyntactic classification. An advantage of the analyzer is its ability to achieve competitive classification accuracy with minimum training data.
A Política Externa da Alemanha após a reunifica??o
Pfetsch, Frank R.;
Revista Brasileira de Política Internacional , 1997, DOI: 10.1590/S0034-73291997000100008
Abstract: analysis of the options opened to the germany after the reunification, emphasizing the international role of frg, its euro-protagonism and its bridge-building function between western europe and eurasia.
Notes on the Mycetophilid With Descriptions of New Species
Frank R. Shaw
Psyche , 1935, DOI: 10.1155/1935/21418
Page 1 /232681
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.