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We derive here the expression for the accretion luminosity, $L(\infty)$, as seen by a distant inertial observer $S_\infty$, for the case of spherical accretion onto a static compact object having a surface gravitational red-shift $z_x$. It is found that the ``efficiency'' for conversion of mass energy into accretion energy is given by $\epsilon = z_x/(1+z_x)$. And since the maximum value of $z_x$ permitted by General Theory of Relativity (GTR) is 2, the maximum theoretical value of the accretion efficiency is 66.66%.

Book digitized by Google from the library of the University of Michigan and uploaded to the Internet Archive by user tpb.

We study the approach in which independent variables describing gravity are functions of the space-time embedding into a flat space of higher dimension. We formulate a canonical formalism for such a theory in a form, which requires imposing additional constraints, which are a part of Einstein's equations. As a result, we obtain a theory with an eight-parameter gauge symmetry. This theory becomes equivalent to Einstein's general relativity either after partial gauge fixing or after rewriting the metric in the form that is invariant under the additional gauge transformations. We write the action for such a theory.

We study the approach in which independent variables describing gravity are functions of the space-time embedding into a flat space of higher dimension. We formulate a canonical formalism for such a theory in a form, which requires imposing additional constraints, which are a part of Einstein's equations. As a result, we obtain a theory with an eight-parameter gauge symmetry. This theory becomes equivalent to Einstein's general relativity either after partial gauge fixing or after rewriting the metric in the form that is invariant under the additional gauge transformations. We write the action for such a theory.

213 p. 21 cm

Book digitized by Google from the library of University of Wisconsin - Madison and uploaded to the Internet Archive by user tpb.

Weinberg Gravitation e cosmological

141p. 23cm

141p. 23cm

141p. 23cm

GDP of China is about 11 trillion dollars and GDP of the United States is about 18 trillion dollars. Suppose that we know for the coming years, economy of the US will experience a real growth rate equal to \%3 and economy of China will experience a real growth as of \%6. Now, the question is how long does it take for economy of China to catch the economy of the United States. The early impression is that the desired time is the answer of the equation $11\times1.06^X=18\times1.03^X$. The correct answer however is quite different. GDP is not a simple number and the gap between two countries can not be addressed simply through their sizes. It is rather a geometrical object. Countries pass different paths in the space of production. The gaps between GDP of different countries depend on the path that each country passes through and local metric. To address distance between economies of China and of the US we need to know their utility preferences and the path that China passes to reach the US size. The true gap then can be found if we calculate local metric along this path. It resembles impressions about measurements in the General Theory of Relativity. Path dependency of aggregate indexes is widely discussed in the Index Number Theory. Our aim is to stick to the geometrical view presented in the General Relativity to provide a visual understanding of the matter. We show that different elements in the general relativity have their own counterparts in economics. We claim that national agencies who provide aggregate data resemble falling observers into a curved space time. It is while the World Bank or international organizations are outside observers. The vision provided here, leaves readers with a clear conclusion. If China keeps its growth rate, then the economy of China should catch the economy of the United States sooner than what we expect.

GDP of China is about 11 trillion dollars and GDP of the United States is about 18 trillion dollars. Suppose that we know for the coming years, economy of the US will experience a real growth rate equal to \%3 and economy of China will experience a real growth as of \%6. Now, the question is how long does it take for economy of China to catch the economy of the United States. The early impression is that the desired time is the answer of the equation $11\times1.06^X=18\times1.03^X$. The correct answer however is quite different. GDP is not a simple number and the gap between two countries can not be addressed simply through their sizes. It is rather a geometrical object. Countries pass different paths in the space of production. The gaps between GDP of different countries depend on the path that each country passes through and local metric. To address distance between economies of China and of the US we need to know their utility preferences and the path that China passes to reach the US size. The true gap then can be found if we calculate local metric along this path. It resembles impressions about measurements in the General Theory of Relativity. Path dependency of aggregate indexes is widely discussed in the Index Number Theory. Our aim is to stick to the geometrical view presented in the General Relativity to provide a visual understanding of the matter. We show that different elements in the general relativity have their own counterparts in economics. We claim that national agencies who provide aggregate data resemble falling observers into a curved space time. It is while the World Bank or international organizations are outside observers. The vision provided here, leaves readers with a clear conclusion. If China keeps its growth rate, then the economy of China should catch the economy of the United States sooner than what we expect.

The Schwarzschild spacetime metric of negative mass is well-known to contain a naked singularity. In a spacelike slice, this singularity of the metric is characterized by the property that nearby surfaces have arbitrarily small area. We develop a theory of such "zero area singularities" in Riemannian manifolds, generalizing far beyond the Schwarzschild case (for example, allowing the singularities to have nontrivial topology). We also define the mass of such singularities. The main result of this paper is a lower bound on the ADM mass of an asymptotically flat manifold of nonnegative scalar curvature in terms of the masses of its singularities, assuming a certain conjecture in conformal geometry. The proof relies on the Riemannian Penrose Inequality. Equality is attained in the inequality by the Schwarzschild metric of negative mass. An immediate corollary is a version of the Positive Mass Theorem that allows for certain types of incomplete metrics.

The Schwarzschild spacetime metric of negative mass is well-known to contain a naked singularity. In a spacelike slice, this singularity of the metric is characterized by the property that nearby surfaces have arbitrarily small area. We develop a theory of such "zero area singularities" in Riemannian manifolds, generalizing far beyond the Schwarzschild case (for example, allowing the singularities to have nontrivial topology). We also define the mass of such singularities. The main result of this paper is a lower bound on the ADM mass of an asymptotically flat manifold of nonnegative scalar curvature in terms of the masses of its singularities, assuming a certain conjecture in conformal geometry. The proof relies on the Riemannian Penrose Inequality. Equality is attained in the inequality by the Schwarzschild metric of negative mass. An immediate corollary is a version of the Positive Mass Theorem that allows for certain types of incomplete metrics.

The Schwarzschild spacetime metric of negative mass is well-known to contain a naked singularity. In a spacelike slice, this singularity of the metric is characterized by the property that nearby surfaces have arbitrarily small area. We develop a theory of such "zero area singularities" in Riemannian manifolds, generalizing far beyond the Schwarzschild case (for example, allowing the singularities to have nontrivial topology). We also define the mass of such singularities. The main result of this paper is a lower bound on the ADM mass of an asymptotically flat manifold of nonnegative scalar curvature in terms of the masses of its singularities, assuming a certain conjecture in conformal geometry. The proof relies on the Riemannian Penrose Inequality. Equality is attained in the inequality by the Schwarzschild metric of negative mass. An immediate corollary is a version of the Positive Mass Theorem that allows for certain types of incomplete metrics.

The Schwarzschild spacetime metric of negative mass is well-known to contain a naked singularity. In a spacelike slice, this singularity of the metric is characterized by the property that nearby surfaces have arbitrarily small area. We develop a theory of such "zero area singularities" in Riemannian manifolds, generalizing far beyond the Schwarzschild case (for example, allowing the singularities to have nontrivial topology). We also define the mass of such singularities. The main result of this paper is a lower bound on the ADM mass of an asymptotically flat manifold of nonnegative scalar curvature in terms of the masses of its singularities, assuming a certain conjecture in conformal geometry. The proof relies on the Riemannian Penrose Inequality. Equality is attained in the inequality by the Schwarzschild metric of negative mass. An immediate corollary is a version of the Positive Mass Theorem that allows for certain types of incomplete metrics.

The quantum theory of ur objects postulates that all existing physical objects and their properties are constructed from fundamental objects called ur objects being described by an element of a two dimensional complex Hilbert space. This approach is based on the assumption that quantum theory represents a theory being constitutive for human knowledge. Physical objects are characterized by the information one can gain from them being contained in the quantum state they are described by. Since every Hilbert space can be represented as a tensor product of two dimensional Hilbert spaces, one is led to the ur objects. According to this approach relativistic quantum fields and thus the existence of a Minkowski space-time are the consequence of an iteration of a quantization of binary alternatives. In the original formulation there was only obtained a description of quantum fields on a flat Minkowski space-time. In this work there is made the attempt to incorporate general relativity and to describe the gravitational field within this approach. Thus the existence of a (3+1)-dimensional space-time in the sense of general relativity is assumed to be a consequence of quantum theory interpreted in an abstract sense.

We consider a few thought experiments of radial motion of massive particles in the gravitational fields outside and inside various celestial bodies: Earth, Sun, black hole. All other interactions except gravity are disregarded. For the outside motion there exists a critical value of coordinate velocity ${\rm v}_c = c/\sqrt 3$: particles with ${\rm v} < {\rm v}_c$ are accelerated by the field, like Newtonian apples, particles with ${\rm v} > {\rm v}_c$ are decelerated like photons. Particles moving inside a body with constant density have no critical velocity; they are always accelerated. We consider also the motion of a ball inside a tower, when it is thrown from the top (bottom) of the tower and after classically bouncing at the bottom (top) comes back to the original point. The total time of flight is the same in these two cases if the initial proper velocity $v_0$ is equal to $c/\sqrt 2$.

A local conception is proposed to reconcile quantum theory with general relativity, which allows one to avoid some difficulties --- as e.g. vacuum catastrophe --- of the global approach.

GTR Notes

This paper is in the public domain in USA. Metadata comes from the CrossRef API, see full record in the source URL below.

Einstein general theory of relativity (GTR) accounted well for the precession of the perihelion of planets and binary pulsars. While the ordinary Newton law of gravitation failed, a generalized version yields similar results. We have shown here that these effects can be accounted for as due to the existence of gravitomagnetism only, and not necessarily due to the curvature of space time. Or alternatively, gravitomagnetism is equivalent to a curved space-time. The precession of the perihelion of planets and binary pulsars may be interpreted as due to the spin of the orbiting planet ($m$) about the Sun ($M$)\,. The spin ($S$) of planets is found to be related to their orbital angular momentum ($L$) by a simple formula, \emph{viz}., $S\propto \,\frac{m}{M}L$\,.

This manuscript introduces a novel geometric framework — RIS-13 (Recursive Identity Space in 13 dimensions) — that proposes a unification of quantum mechanics and general relativity via consciousness transmission theory. The RIS-13 structure is built as a product manifold of a 7-dimensional G₂ holonomy space and a 6-dimensional Calabi–Yau manifold: 𝓒 = M⁷_{G₂} × M⁶_{CY} It presents the first full variational action where: • Quantum probabilities emerge from projector operators grounded in recursive identity tracking   • General relativity is recovered through an Einstein–Hilbert term on the 13D manifold   • A dynamic consciousness field \( Xᵢ : M⁴ → 𝓒 \) interacts with the physical universe through its stress-energy tensor \( T^{consc}_{μν} \) This work bridges physics and philosophy, offering a new pathway for understanding spacetime, perception, and fundamental forces via mathematically tractable identity propagation.

vi p., 1 l., 218 p., 1 l. 23 cm

We show that representations of the group of spacetime diffeomorphism and the Dirac algebra both arise in a phase-space histories version of canonical general relativity. This is the general-relativistic analogue of the novel time structure introduced previously in history theory: namely, the existence in non-relativistic physics of two types of time translation; and the existence in relativistic field theory of two distinct Poincare groups.

No Abstract Available

No Abstract Available

By his theory of relativity Albert Einstein has provoked a revolution of thought in physical science. The achievement consists essentially in this:�Einstein has succeeded in separating far more completely than hitherto the share of the observer and the share of external nature in the things we see happen. The perception of an object by an observer depends on his own situation and circumstances; for example, distance will make it appear smaller and dimmer. We make allowance for this almost unconsciously in interpreting what we see. But it now appears that the allowance made for the motion of the observer has hitherto been too crude�a fact overlooked because in practice all observers share nearly the same motion, that of the earth. Physical space and time are found to be closely bound up with this motion of the observer; and only an amorphous combination of the two is left inherent in the external world. When space and time are relegated to their proper source�the observer�the world of nature which remains appears strangely unfamiliar; but it is in reality simpli�ed, and the underlying unity of the principal phenomena is now clearly revealed. The deductions from this new outlook have, with one doubtful exception, been con�rmed when tested by experiment. It is my aim to give an account of this work without introducing anything very technical in the way of mathematics, physics, or philosophy. The new view of space and time, so opposed to our habits of thought, must in any case demand unusual mental exercise. The results appear strange; and the incongruity is not without a humorous side. For the �rst nine chapters the task is one of interpreting a clear-cut theory, accepted in all its essentials by a large and growing school of physicists�although perhaps not everyone would accept the author�s views of its meaning. Chapters x and xi deal with very recent advances, with regard to which opinion is more �uid. As for the last chapter, containing the author�s speculations on the meaning of nature, since it touches on the rudiments of a philosophical system, it is perhaps too sanguine to hope that it can

Nonstandard analysis and electromagnetic propagation properties are used to derive all of the fundamental results for the Special Theory of Relativity. Infinitesimal modeling via infinitesimal light-clocks is used to derive two general line-elements (metrics) without the use of Riemannian geometry. By substituting potential velocities, the Schwarzschild, quasi and modified Schwarzschild, de Sitter, Robertson-Walker and similar line-elements are derived. New black hole and quasi-white hole investigations are presented. A new fixed method using separating operators is used to obtain the major predictions for the relativistic alterations in natural-system behavior. The major conclusion is that all such changes are related to electromagnetic properties and that Riemannian geometry is but an analogue model for natural-system behavior.

Nonstandard analysis and electromagnetic propagation properties are used to derive all of the fundamental results for the Special Theory of Relativity. Infinitesimal modeling via infinitesimal light-clocks is used to derive two general line-elements (metrics) without the use of Riemannian geometry. By substituting potential velocities, the Schwarzschild, quasi and modified Schwarzschild, de Sitter, Robertson-Walker and similar line-elements are derived. New black hole and quasi-white hole investigations are presented. A new fixed method using separating operators is used to obtain the major predictions for the relativistic alterations in natural-system behavior. The major conclusion is that all such changes are related to electromagnetic properties and that Riemannian geometry is but an analogue model for natural-system behavior.

Nonstandard analysis and electromagnetic propagation properties are used to derive all of the fundamental results for the Special Theory of Relativity. Infinitesimal modeling via infinitesimal light-clocks is used to derive two general line-elements (metrics) without the use of Riemannian geometry. By substituting potential velocities, the Schwarzschild, quasi and modified Schwarzschild, de Sitter, Robertson-Walker and similar line-elements are derived. New black hole and quasi-white hole investigations are presented. A new fixed method using separating operators is used to obtain the major predictions for the relativistic alterations in natural-system behavior. The major conclusion is that all such changes are related to electromagnetic properties and that Riemannian geometry is but an analogue model for natural-system behavior.

The problem of time in canonical quantum gravity is related to the fact that the canonical description is based on the prior choice of a spacelike foliation, hence making a reference to a spacetime metric. However, the metric is expected to be a dynamical, fluctuating quantity in quantum gravity. We show how this problem can be solved in the histories formulation of general relativity. We implement the 3+1 decomposition using metric-dependent foliations which remain spacelike with respect to all possible Lorentzian metrics. This allows us to find an explicit relation of covariant and canonical quantities which preserves the spacetime character of the canonical description. In this new construction, we also have a coexistence of the spacetime diffeomorphisms group, and the Dirac algebra of constraints.

This paper is devoted to the evaluation of the energy-momentum density components for the Friedmann models. For this purpose, we have used M${\o}$ller's pseudotensor prescription in General Relativity and a certain energy-momentum density developed from his teleparallel formulation. It is shown that the energy density of the closed Friedmann universe vanishes on the spherical shell at the radius $\rho=2\sqrt{3}$. This coincides with the earlier results available in the literature. We also discuss the energy of the flat and open models. A comparison shows a partial consistency between the M${\o}$ller's pseudotensor for General Relativity and teleparallel theory. Further, it is shown that the results are independent of the free dimensionless coupling constant of the teleparallel gravity.

The theory of evolution equations has been applied in various ways in general relativity. Following some general considerations about this, some illustrative examples of the use of ordinary differential equations in general relativity are presented. After this recent applications of Fuchsian equations are described, with particular attention to work on the structure of singularities of solutions of the Einstein equations coupled to a massless scalar field. Next the relations between analytical and numerical studies of the Einstein equations are discussed. Finally an attempt is made to identify fruitful directions for future research within the analytic approach to the study of the Einstein equations.

Book Source: Digital Library of India Item 2015.212348 dc.contributor.other: Indian Institute Of Science dc.date.accessioned: 2015-07-09T17:56:08Z dc.date.available: 2015-07-09T17:56:08Z dc.date.digitalpublicationdate: 0000-00-00 dc.date.citation: 1921 dc.identifier: IISc Library dc.identifier.barcode: 1010010081076 dc.identifier.origpath: /data_copy/upload/0081/081 dc.identifier.copyno: 1 dc.identifier.uri: http://www.new.dli.ernet.in/handle/2015/212348 dc.description.scanningcentre: IISc, Bangalore dc.description.main: 1 dc.description.tagged: 0 dc.description.totalpages: 218 dc.format.mimetype: application/pdf dc.language.iso: English dc.publisher.digitalrepublisher: Indian Institute Of Science dc.rights: Out_of_copyright dc.source.library: Iisc Library dc.subject.classification: Physics dc.title: Space Time And Gravitation An Outline Of The General Relativity Theory

This is the PDF of Einstein, Hilbert, and the Theory of Gravitation - Historical Origins of General Relativity Theory by Jagdish Mehra. I have no monetary benefits from this work and it is intended for non-commercial uses only

This is the PDF of Einstein, Hilbert, and the Theory of Gravitation - Historical Origins of General Relativity Theory by Jagdish Mehra. I have no monetary benefits from this work and it is intended for non-commercial uses only

The simplest variant of gauge gravitation theory in Riemann-Cartan spacetime leading to the solution of the problem of cosmological singularity and dark energy problem is investigated. It is shown that this theory by certain restrictions on indefinite parameters of gravitational Lagrangian in the case of usual gravitating systems leads to Einstein gravitational equations with effective cosmological constant.

Klangforum Wien Wojciech Błażejczyk _ General Theory of Relativity 2021 [FLAC 24-96]

It is shown that Einstein gravity in four dimensions with small cosmological constant and small extra dimensions can be obtained by spontaneous compactification of Lovelock gravity in vacuum. Assuming that the extra dimensions are compact spaces of constant curvature, General Relativity is recovered within certain class of Lovelock theories possessing necessarily cubic or higher order terms in curvature. This bounds the higher dimension to be at least seven. Remarkably, the effective gauge coupling and Newton constant in four dimensions are not proportional to the gravitational constant in higher dimensions, but shifted with respect to their standard values. This effect opens up new scenarios where a maximally symmetric solution in higher dimensions could decay into the compactified spacetime either by tunneling or through a gravitational analogue of ghost condensation. Indeed, this is what occurs requiring both the extra dimensions and the four-dimensional cosmological constant to be small.

It is shown that Einstein gravity in four dimensions with small cosmological constant and small extra dimensions can be obtained by spontaneous compactification of Lovelock gravity in vacuum. Assuming that the extra dimensions are compact spaces of constant curvature, General Relativity is recovered within certain class of Lovelock theories possessing necessarily cubic or higher order terms in curvature. This bounds the higher dimension to be at least seven. Remarkably, the effective gauge coupling and Newton constant in four dimensions are not proportional to the gravitational constant in higher dimensions, but shifted with respect to their standard values. This effect opens up new scenarios where a maximally symmetric solution in higher dimensions could decay into the compactified spacetime either by tunneling or through a gravitational analogue of ghost condensation. Indeed, this is what occurs requiring both the extra dimensions and the four-dimensional cosmological constant to be small.

213 p. 21 cm

213 p. 21 cm

213 p. 21 cm

Book: Gravitation and Cosmology: Principles and Applications of The General Theory of Relativity by Steven Weinberg (MIT) Publisher: John Wiley & Sons, Inc. ISBN 0-471-92567--5 Pages: 685

Book: Gravitation and Cosmology: Principles and Applications of The General Theory of Relativity by Steven Weinberg (MIT) Publisher: John Wiley & Sons, Inc. ISBN 0-471-92567--5 Pages: 685

We study the Robertson-Walker type model in the Lyttleton-Bondi universe in five dimensional general theory of relativity. Some exact and physical properties of solutions are discussed.

An intersection of Yang-Mills theory with the gauge description of general relativity is considered. This intersection has its origin in a generalized algebra, where the generators of the SO(3,1) group as gauge group of general relativity and the generators of a SU(N) group as gauge group of Yang-Mills theory are not separated anymore but are related by fulfilling nontrivial commutation relations with each other. Because of the Coleman Mandula theorem this algebra cannot be postulated as Lie algebra. As consequence, extended gauge transformations as well as an extended expression for the field strength tensor is obtained, which contains a term consisting of products of the Yang Mills connection and the connection of general relativity. Accordingly a new gauge invariant action incorporating the additional term of the generalized field strength tensor is built, which depends of course on the corresponding tensor determining the additional intersection commutation relations. This means that the theory describes a decisively modified interaction structure between the Yang-Mills gauge field and the gravitational field leading to a violation of the equivalence principle.

We modify the Einstein-Schrodinger theory to include a cosmological constant $\Lambda_z$ which multiplies the symmetric metric, and we show how the theory can be easily coupled to additional fields. The cosmological constant $\Lambda_z$ is assumed to be nearly cancelled by Schrodinger's cosmological constant $\Lambda_b$ which multiplies the nonsymmetric fundamental tensor, such that the total $\Lambda=\Lambda_z+\Lambda_b$ matches measurement. The resulting theory becomes exactly Einstein-Maxwell theory in the limit as $|\Lambda_z|\to\infty$. For $|\Lambda_z|\sim 1/(Planck length)^2$ the field equations match the ordinary Einstein and Maxwell equations except for extra terms which are $

We present a fractal dust model of the Universe based on Mandelbrot's proposal to replace the standard Cosmological Principle by his Conditional Cosmological Principle within the framework of General Theory of Relativity. This model turns out to be free from the de-Vaucouleurs paradox and is consistent with the SNe1a observations. The expected galaxy count as a function of red-shift is obtained for this model. An interesting variation is a steady state version, which can account for an accelerating scale factor without any cosmological constant in the model.