arXiv subjects

Yousef Sobouti

Publications and source records attributed to Yousef Sobouti.

8 recordsLinked to original sources

arXiv2025

Remove point-mass concept-remove singularities from GR

Singularities in Newton's gravitation, in general relativity (GR), in Coulomb's law, and elsewhere in classical physics, stem from two ill conceived assumptions: a) there are point-like entities with finite masses, charges, etc., packed in zero volumes, and b) the non-quantum assumption that these point-likes can be assigned precise coordinates and momenta. In the case of GR, we argue that the classical energy-momentum tensor in Einstein's field equation is that of a collection of point particles and is prone to singularity. In compliance with Heisenberg's uncertainty principle, we suggest to replace each constituent of the gravitating matter with a suitable quantum mechanical equivalent, here a Klien-Gordon (KG) or a Yukawa-ameliorated version of it, YKG field. KG and YKG fields are spatially distributed entities. They do not end up in singular spacetime points nor predict singular blackholes. On the other hand, YKG waves reach infinity as $\frac{1}{r}e^{-(κ\pm i k)r}$. They create the Newtonian $r^{-2}$ term as well as a non-Newtonian $r^{-1}$ force. The latter is capable of explaining the observed flat rotation curves of spiral galaxies, and is interpretable as an alternative gravity, a dark matter scenario, etc. There are ample observational data on flat rotation curves of spiral galaxies, coded in the Tully-Fisher relation, to support our propositions.

physics.gen-ph↗

arXiv2022

Three arguable and interrelated concepts: point particle singularity, asymmetric action of EM on quantum wave functions, and the Left out restricted Lorentz gauge from U(1)

We address three issues. i. The point particle assumption, inherent to non-quantum physics, is singular and entails divergent fields and integrals. ii. In quantum physics EM plays an asymmetric roll. It acts on quantum wave fields (wave functions) but the wave fields do not react back. We suggest to promote the one sided action of EM on quantum fields into a mutual action-reaction partnership. By so doing, the quantum wave shares its analyticity with the EM field and removes the later's singularities and divergences. iii) The conventional U(1) symmetry leaves quantum dynamics invariant under a 'general' Lorentz gauge and impose the standard minimal coupling of the quantum wave to the Em 4-vector potential. One, however, has the option to ask for in-variance under the 'restricted' Lorentz gauge. This in turn invites in a coupling to derivatives of the vector potential in addition to the minimal coupling and, so to say, enlarges the U(1) symmetry. We find that the electron exhibits distributed charge- and current- densities. The enlarged symmetry is expected to bring in its own constant of motion. Indeed it does. The anomalous g-factor of the so designed electron emerges, up to order (α/π)^2 as the new constant of motion but, without invoking the QED formalism.

physics.class-ph↗

arXiv2013

Minimalist's Electromagnetism - Different Axioms and Different Insight

That the speed of light is a universal constant is a logical consequence of Maxwell's equations. Here we show the converse is also true. Electromagnetism (EM) and electrodynamics (ED), in all details, can be derived from two simple assumptions: i) the speed of light is a universal constant and, ii) the common observations that there are the so-called charged particles that interact with each other. Conventional EM and ED are observation based. The proposed alternative spares all those observational foundations, only to reintroduce them as theoretically derived and empiricism-free laws of Nature. There are merits to simplicity. For instance, when one learns that Poisson's equation emerges as a corollary of the formalism, one immediately concludes that Coulomb's $1/r^2$ law of force is exact. Or, if it turns out that $\nabla.\mathbf{B}=0$ follows from the theory, then non-existence of (at least classical) magnetic monopoles will be an exact law of Nature. The list is longer than the these two examples.

physics.class-ph↗

arXiv2013

Revised dynamics or dark matter in galactic and extra galactic scales?

Allowing the energy of a gravitational field to serve partially as its own source allows gravitating bodies to exhibit stronger fields, as if they were more massive. Depending on degree of compaction of the body, the field could be one to five times larger than the newtonian field. This is a comfortable range of increase in field strength and may prove to be of convenience in the study of velocity curves of spirals, of velocity dispersions in clusters of galaxies and in interpreting the Tully-Fisher or Faber-Jackson relations in galaxies or systems of galaxies. The revised gravitation admits of superposition principle but only approximately in systems whose components are widely separated. The revised dynamics admits of the equivalence principle in that, the effective force acting on a test particle is derived from a potential, and could be eliminated in a freely falling frame of reference

astro-ph↗

arXiv2009

Dark companion of Baryonic matter, III

Wherever one talks of dark matter, one does so where there is an observable matter and an associated unsolved dynamical issue to be settled. We promote this observation to the status of an axiom and conjecture that there is a dark companion to every baryonic matter, subject to certain rules as regards its size, distribution. To pursue the proposition in a systematic way we resort to the rotation curves of spiral galaxies. They have non classical features. First, we design a spacetime metric around the galaxy to accommodate these features. Next we calculate the density and pressure of a hypothetical dark matter that could generate such a spacetime. In the weak field regime and for a spherical distribution of mass $M$, we are able to assign a dark perfect gas companion, whose density is almost proportional to $M^{1/2}$ and fades away almost as $r^{-2}$. However, in view of this orderly relation between the observable mass and its dark companion, one may choose to interpret the whole scenario as an alternative theory of gravitation.

gr-qc↗

arXiv2009

Dark companion of baryonic matter in spliral galaxies

Flat or almost flat rotation curves of spiral galaxies can be explained by logarithmic gravitational potentials. The field equations of GR admit of spacetime metrics with such behaviors. The scenario can be interpreted either as an alternative theory of gravitation or, equivalently, as a dark matter paradigm. In the latter interpretation, one is led to assign a dark companion to the baryonic matter who's size and distribution is determined by the mass of the baryons. The formalism also opens up a way to support Milgrom's idea that the acceleration of a test object in a gravitational field is not simply the newtonian gravitational force $g_N$, but rather an involved function of $(g_N/a_0)$, $a_0$ MOND's universal acceleration. Keywords: Dark matter; Alternative GR; Spiral galaxies, rotation curves of

gr-qc↗

arXiv2008

Dark companion of baryonic matter

Whenever and wherever one talks of dark matter, one does so when and where there is a luminous matter and a dynamical issue to be settled. We promote this observation to the status of an axiom and assume that there is a dark companion to every luminous matter and there are orders to this companionship. To pursue the proposition in a formal and quantitative manner, we consider the anomalous rotation curves of spiral galaxies. From the available observations, we infer the gravitational potential prevailing in the outer parts of the galaxy and, thereof, construct the tt- component of the metric of the embedding spacetime. Next we examine a perfect fluid candidate as the dark companion and solve the relevant GR equations. We are able to determine the strength and the distribution of the dark fluid that accompanies a point baryonic mass. Finally, we argue that the whole paradigm can be explained just as well in terms of an alternative theory. Keywords: Dark matter; Alternative GR; Spiral galaxies, rotation curves of

gr-qc↗

arXiv2007

An Inverse $f(R)$ Gravitation for Cosmic Speed up, and Dark Energy Equivalent

To explain the cosmic speed up, brought to light by the recent SNIa and CMB observations, we propose the following: a) In a spacetime endowed with a FRW metric, we choose an empirical scale factor that best explains the observations. b) We assume a modified gravity, generated by an unspecified field lagrangian, $f(R)$. c) We use the adopted empirical scale factor to work back retroactively to obtain $f(R)$, hence the term `Inverse $f(R)$'. d) Next we consider the classic GR and a conventional FRW universe that, in addition to its known baryonic content, possesses a hypothetical `Dark Energy' component. We compare the two scenarios, and find the density, the pressure, and the equation of the state of the Dark Energy required to make up for the differences between the conventional and the modified GR models.

astro-ph↗