Astrophysics

1112 Submissions

[3] viXra:1112.0075 [pdf] submitted on 2011-12-26 15:45:48

Modified Newtonian Dynamics and Dark Matter from a Generalized Gravitational Theory

Authors: Juan Ramón González Álvarez
Comments: 9 Pages.

Vast amounts of data clearly demonstrate discrepancies between the observed dynamics, in large astronomical systems, and the predicted dynamics by Newtonian gravity and general relativity. The appearance of these discrepancies has two possible explanations: either these systems contain large quantities of a new kind of unseen matter −the Dark Matter (DM)− or the gravitational law has to be modified at this scale −as in MOdified Newtonian Dynamics (MOND)−. This dichotomy is not entirely new in the history of physics, with DM playing now the role of the old non-existent Vulcan planet.

We have shown how both (i) the MONDian form and (ii) Milgrom acceleration follow from an extended theory of gravity −characterized by a new kind of gravitational potentials hμν(R(t))−, which (iii) was initially aimed to solve those deficiencies of general relativity shared with classical electrodynamics −and that were previously solved with new electromagnetic potentials Φ(R(t)) and A(R(t))−. We also show (iv) how the modified equation of motion can be cast into ordinary form, when an fictitious distribution of DM matter is added to the real mass. From our definition of DM, we obtain (v) the main properties traditionally attributed to it, in excellent agreement with the DM literature. Finally, (vi) we discuss further avenues of research opened by this new paradigm.


Category: Astrophysics

[2] viXra:1112.0020 [pdf] submitted on 2011-12-07 07:36:55

Classical and Quantum Limits in Unified GTR

Authors: U.V.S.Seshavatharam
Comments: 16 Pages. U. V. S. Seshavatharam and S. Lakshminarayana. Uni ed model of universe and the atom. Book. ISBN: 9783843393966, LAP LAMBERT Academic Publishing GmbH & Co. KG, Germany, 2011 March.

It is noticed that $\frac{c^4}{G}$ is the classical limit of force and ($\frac{c^5}{G}$ is the classical limit of power. With these two limits, mathematical complexity involved in GTR can be simplified. Planck mass can be derived very easily. Light speed rotating black hole’s formation can be understood. Force $\frac{c^4}{G}$ keeps the light speed rotating black hole stable. It is noticed that, any elementary particle can escape from the light speed rotating black hole’s equator. Origin of cosmic ray can be understood in this view. GTR and quantum mechanics can be coupled in a unified manner. Rotating black hole temperature formula can be derived very easily. Finally a rotating model of ’black hole cosmology’ can be developed.
Category: Astrophysics

[1] viXra:1112.0014 [pdf] replaced on 2013-05-07 14:14:43

A New Model Without Dark Matter for the Rotation of Spiral Galaxies: the Connections Among Shape, Kinematics and Evolution

Authors: Mario Everaldo de Souza
Comments: 10 Pages. Presented at the APS April 2013 Meeting , Denver, CO, USA, published at Frontiers in Science, 3(2), 2013

It is proposed that the arms of spiral galaxies are formed by the continuous outflow of matter from their centers. It is then shown that the ratio between the radial and tangential velocities of the outflow is the parameter responsible for the logarithmic spiral structure of spiral galaxies. The fitting of some spiral galaxies to the model allows the calculation of the expansion velocities of matter in these galaxies and such values completely agree with the observational data. An approximate universal equation is proposed for the description of the arms of spiral galaxies with or without bars. Some important consequences are discussed with respect to dark matter, galactic evolution, cosmology, and the Milky Way. It is, particularly, concluded that dark matter does not exist in spiral galaxies.
Category: Astrophysics