Ultimate gravitational mass defect

Fortschritte der Physik/Progress of Physics, 1988

Focus on Black Hole Research, 2006

We critically review here the concepts which gave rise to the Black Hole (BH) paradigm over almost past 90 years. First we point out that the very attempt to find the spacetime around a "Massenpunkt" (Point Mass) implicitly forced the entry of Point Singularities in General Relativity (GR). And it is this borrowed Newtonian idea of a "Point Mass" which directly laid the foundation of the BH paradigm in GR. We show that in order that neither any geometrical nor any physical scalar related to the metric associated with a Massenpunkt diverges in a region which is not a physical singularity, the mass of an uncharged Massenpunkt (i.e., the BH), obtained as an integration constant, must be M 0 = 0. This result agrees exactly with the result found by Arnowitt, Deser & Misner way back in 1962: "a neutral particle (one coupled only to gravitational field) has a zero clothed mass, showing that the mass of the particle arises entirely from its interaction with other field" (however, for a neutral finite body, of course there would be finite clothed mass). If the point particle is charged, again, it would have finite mass, and it can be shown, that, mathematically GR allows existence of charged BHs. But, astrophysical BHs are uncharged, and, in this review a BH would mean a non-rotating neutral BH unless mentioned otherwise.

Starting from the weak field limit, we discuss astrophysical applications of Extended Theories of Gravity where higher order curvature invariants and scalar fields are considered by generalizing the Hilbert-Einstein action linear in the Ricci curvature scalar R. Results are compared to General Relativity in the hypothesis that Dark Matter contributions to the dynamics can be neglected thanks to modified gravity. In particular, we consider stellar hydrostatic equilibrium, galactic rotation curves, and gravitational lensing. Finally, we discuss the weak field limit in the Jordan and Einstein frames pointing out how effective quantities, as gravitational potentials, transform from one frame to the other and the interpretation of results can completely change accordingly.

Explosive energy in the nucleus of the galaxy NGC 3034 composed 9 • 10 48 J. In this case of its nucleus of galaxy was rejected the mass equal to 5,9 • 10 7 of the masses of the sun. At present are not known the physical mechanisms, which can explain such immense explosions. In the article is examined the new physical phenomenon, gravitational mass defect, which can explain the phenomenon indicated. This phenomenon leads to the fact that the summary mass of bodies before and after the collisions differ. Indicated we will call mass defect gravitational mass defect and it can serve as a reason for explosions in the nuclei of galaxies.

Modern Physics Letters A, 2015

The method of characteristics is a key tool for studying consistency of equations of motion; it allows issues such as predictability, maximal propagation speed, superluminality, unitarity and acausality to be addressed without requiring explicit solutions. We review this method and its application to massive gravity (mGR) theories to show the limitations of these models' physical viability: Among their problems are loss of unique evolution, superluminal signals, matter coupling inconsistencies and micro-acausality (propagation of signals around local closed time-like curves (CTCs)/closed causal curves (CCCs)). We extend previous no-go results to the entire three-parameter range of mGR theories. It is also argued that bimetric models suffer a similar fate.

Journal of Mathematical Physics, 2009

In a recent paper, Castro (J. Math. Phys., 49, 042501, 2008)[1] has mentioned that in two papers, Mitra (Found. Phys. Lett., 13, 543, 2002)[2] and ( MNRAS, 369, 492, 2006)[3], (i) attempted to show that a neutral point particle has zero gravitational mass, but (ii) his intended proof was faulty and can be "bypassed". In reality, none of these two papers offered any such proof and on the other hand this proof could be found in (Adv. Sp. Res. 38 ] not considered/cited by Castro. This shows that Castro critisized Mitra's "proof" without really going through it. We briefly revisit this "proof" to show that it is indeed correct and does not suffer from perceived shortcomings. It is reminded that Arnowitt, Deser & Misner's (ADM) previous work work suggested that the gravitational mass of a neutral point particle is zero. It is pointed out that that this result has important implications for Castro's work. Further the mass formula M = 4πρr 2 dr used by Castro may not be valid for the radial gauge he used, and the "spacetime void" inferred by Castro may be an artifact of the discontinuos radial gauge used by him. * Electronic address: [email protected]

2012

In this paper, by reviewing old as well as modern controversial findings, it was shown that gravity is a single unique phenomenon that after appearance attracts mass and particles around itself. This makes a misunderstanding of mass-gravity relation as cause and effect. Here, a discussion was put ahead, which concludes that mass; and actually energy condensation, cannot create gravity and it would be shown that there is no need to correlate mass with gravity. Instead it is shown that existence of something that can be called a gravity generator is the real cause of gravity and in stable celestial objects the mass around that gravity generator is only a manifestation of the severity of space-time shrinkage created by that generator. Key words: General relativity, mass-gravity relation, gravity generator.

General Relativity and Gravitation

An original way of presentation of the Schwarzschild black hole in the form of a point-like mass with making the use of the Dirac δ-function, including a description of a continuous collapse to such a point mass, is given. A maximally generalized description restricted by physically reasonable requirements is developed. A so-called field-theoretical formulation of general relativity, being equivalent to the standard geometrical presentation of general relativity, is used. All of the dynamical fields, including the gravitational field, are considered as propagating in a background (curved or flat) spacetime. Namely these properties allow us to present a non-contradictive picture of the point mass description. The results can be useful for studying the structure of the black hole true singularities and could be developed for practical calculations in models with black holes. Keywords General relativity • black holes • regular collapse • true singularity 1 Introduction: motivation and goals The Schwarzschild solution [1,2] in general relativity (GR) has been obtained under the simplest assumptions: it has to be a vacuum, spherically symmetric and static one. A choice of the integration constant, M , corresponds to the assumption that the solution is induced by isolated gravitational masses with the Newtonian asymptotic behaviour. All of these means that a source could be a point particle (point mass). However, one finds that the Schwarzschild solution is a black hole solution, whereas the notion of a point mass in GR

International Journal of Astronomy and Astrophysics, 2013

The purpose of the present paper is to assume that the expanding spacetime of our cosmos was created by the big bang. It then follows that there exists a finite instantaneous radial extent dR U to spacetime as observed from anywhere in spacetime by comoving observers. The consequences for gravity are explored by first considering the scalar field of a central mass that defines the dynamic properties of a circular orbit for each radius R ≤ dR U under the postulate of weak equivalence. These properties include an orbital velocity and an escape velocity. For a central mass of galactic proportion, the escape velocity becomes large even at cosmological distances. By considering the dynamics of a smaller mass occupying the last orbit, we find that the established laws of physics lead to different rotation curves than they do when applied to the solar system. Since galactic rotation curves reveal the existence of dark matter, this is anticipated to have some consequences for our understanding of dark matter.

A continuous family of static spherically symmetric solutions of Einstein's vacuum field equations with a spatial singularity at the origin r = 0 is found. These solutions are parametrized by a real valued parameter λ (ranging from 0 to ∞) and such that the radial horizon's location is displaced continuously towards the singularity (r = 0) as λ increases. In the limit λ → ∞, the location of the singularity and horizon merges leading to a null singularity. In this extreme case, any infalling observer hits the null singularity at the very moment he/she crosses the horizon. This fact may have important consequences for the resolution of the fire wall problem and the complementarity controversy in black holes. Another salient feature of these solutions is that it leads to a modification of the Newtonian potential consistent with the effects of the generalized uncertainty principle (GUP) associated to a minimal length. The field equations due to a delta-function point-mass source at r = 0 are solved and the Euclidean gravitational action corresponding to those solutions is evaluated explicitly. It is found that the Euclidean action is precisely equal to the black hole entropy (in Planck area units). This result holds in any dimensions D ≥ 3. The study of the Nonperturbative Renormalization Group flow of the metric g µv [k] in terms of the momentum scale k and its relationship to these family of metrics parametrized by λ deserves further investigation.