scholarly journals Space–time singularities and cosmic censorship conjecture: A Review with some thoughts

2020 ◽  
Vol 35 (14) ◽  
pp. 2030007 ◽  
Author(s):  
Yen Chin Ong
Keyword(s):  
General Relativity ◽  
Short Review ◽  
Big Bang ◽  
Cosmic Censorship ◽  
Space Time ◽  
Singularity Theorems ◽  
Time Singularities ◽  
The One ◽  
The Big Bang ◽  
Cosmic Censorship Conjecture

The singularity theorems of Hawking and Penrose tell us that singularities are common place in general relativity. Singularities not only occur at the beginning of the Universe at the Big Bang, but also in complete gravitational collapses that result in the formation of black holes. If singularities — except the one at the Big Bang — ever become “naked,” i.e. not shrouded by black hole horizons, then it is expected that problems would arise and render general relativity indeterministic. For this reason, Penrose proposed the cosmic censorship conjecture, which states that singularities should never be naked. Various counterexamples to the conjecture have since been discovered, but it is still not clear under which kind of physical processes one can expect violation of the conjecture. In this short review, I briefly examine some progresses in space–time singularities and cosmic censorship conjecture. In particular, I shall discuss why we should still care about the conjecture, and whether we should be worried about some of the counterexamples. This is not meant to be a comprehensive review, but rather to give an introduction to the subject, which has recently seen an increase of interest.

scholarly journals Unified Explanation of Big Bang, Inflation, Charged Black Hole Decay, Galaxy Formation, Proton Spin Crisis and Elementary Particle Masses

2021 ◽  
Author(s):  
Jae-Kwang Hwang
Keyword(s):  
Black Holes ◽  
Euclidean Space ◽  
Big Bang ◽  
Space Time ◽  
Proton Spin ◽  
Gravitational Forces ◽  
Normal Matter ◽  
Dark Matters ◽  
Spin Crisis ◽  
The Big Bang

Space-time evolution is briefly explained by using the 3-dimensional quantized space model (TQSM) based on the 4-dimensional (4-D) Euclidean space. The energy (E=cDtDV), charges (|q|= cDt) and absolute time (ct) are newly defined based on the 4-D Euclidean space. The big bang is understood by the space-time evolution of the 4-D Euclidean space but not by the sudden 4-D Minkowski space-time creation. The big bang process created the matter universe with the positive energy and the partner anti-matter universe with the negative energy from the CPT symmetry. Our universe is the matter universe with the negative charges of electric charge (EC), lepton charge (LC) and color charge (CC). This first universe is made of three dark matter -, lepton -, and quark - primary black holes with the huge negative charges which cause the Coulomb repulsive forces much bigger than the gravitational forces. The huge Coulomb forces induce the inflation of the primary black holes, that decay to the super-massive black holes. The dark matter super-massive black holes surrounded by the normal matters and dark matters make the galaxies and galaxy clusters. The spiral arms of galaxies are closely related to the decay of the 3-D charged normal matter black holes to the 1-D charged normal matter black holes. The elementary leptons and quarks are created by the decay of the normal matter charged black holes, that is caused by the Coulomb forces much stronger than the gravitational forces. The Coulomb forces are very weak with the very small Coulomb constants (k1(EC) = kdd(EC) ) for the dark matters and very strong with the very big Coulomb constants (k2(EC) = knn(EC)) for the normal matters because of the non-communication of the photons between the dark matters and normal matters. The photons are charge dependent and mass independent. But the dark matters and normal matters have the similar and very weak gravitational forces because of the communication of the gravitons between the dark matters and normal matters. The gravitons are charge independent and mass dependent. Note that the three kinds of charges (EC, LC and CC) and one kind of mass (m) exist in our matter universe. The dark matters, leptons and quarks have the charge configurations of (EC), (EC,LC) and (EC,LC,CC), respectively. Partial masses of elementary fermions are calculated, and the proton spin crisis is explained. The charged black holes are not the singularities.

scholarly journals Augustine of Hippo’s Philosophy of Time Meets General Relativity

KronoScope ◽  
2014 ◽  
Vol 14 (1) ◽  
pp. 71-89 ◽  
Author(s):  
Ettore Minguzzi
Keyword(s):  
General Relativity ◽  
Cosmological Model ◽  
Degrees Of Freedom ◽  
Big Bang ◽  
Null Hypersurface ◽  
Philosophy Of Time ◽  
The Big Bang ◽  
The Universe

Abstract This paper proposes a cosmological model that uses a causality argument to solve the homogeneity and entropy problems of cosmology. In this model, a chronology violating region of spacetime causally precedes the remainder of the Universe, and a theorem establishes the existence of time functions precisely outside the chronology violating region. This model is shown to nicely reproduce Augustine of Hippo’s thought on time and the beginning of the Universe. In the model, the spacelike boundary representing the Big Bang is replaced by a null hypersurface at which the gravitational degrees of freedom are almost frozen while the matter and radiation content is highly homogeneous and thermalized.

Observations which contradict the hypothesis of a big bang universe

1994 ◽  
Vol 2 (2) ◽  
pp. 165-172
Author(s):  
Halton Arp
Keyword(s):  
General Relativity ◽  
Big Bang ◽  
Correct Solution ◽  
Expanding Universe ◽  
Fundamental Assumption ◽  
Continuous Creation ◽  
Observational Test ◽  
Big Bang Theory ◽  
The Big Bang ◽  
Recession Velocity

The Big Bang theory requires all matter and galaxies to have been created simultaneously 15 billion years ago. But many young galaxies have been observed which must have been created more recently. Moreover, these younger objects, although demonstrably nearby, have large redshifts which cannot be due to recession velocity in an expanding universe. The fundamental assumption in the Big Bang is that extragalactic redshifts are caused only by the velocity of recession. It is shown here how every observational test which can be made on galaxies, and even stars, contradicts the assumption. It is described how a more general and more correct solution of the Einstein general relativity equations yields a non-expanding, continuous creation universe of unlimited age and size.

scholarly journals THE INTERFACE OF COSMOLOGY WITH STRING AND M(ILLENNIUM) THEORY

2001 ◽  
Vol 16 (30) ◽  
pp. 4803-4843 ◽  
Author(s):  
DAMIEN A. EASSON
Keyword(s):  
Early Universe ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Short Review ◽  
Big Bang ◽  
Space Time ◽  
String Cosmology ◽  
Brane World ◽  
Recent Developments ◽  
M Theory

The purpose of this review is to discuss recent developments occurring at the interface of cosmology with string and M theory. We begin with a short review of 1980s string cosmology and the Brandenberger–Vafa mechanism for explaining space–time dimensionality. It is shown how this scenario has been modified to include the effects of p-brane gases in the early universe. We then introduce the Pre-Big-Bang scenario (PBB), Hořava–Witten heterotic M theory and the work of Lukas, Ovrut and Waldram, and end with a discussion of large extra dimensions, the Randall–Sundrum model and Brane World cosmologies.

A THEORY OF SPACE, TIME AND MATTER

1996 ◽  
Vol 11 (18) ◽  
pp. 3247-3255 ◽  
Author(s):  
P.S. WESSON ◽  
J. PONCE DE LEON ◽  
H. LIU ◽  
B. MASHHOON ◽  
D. KALLIGAS ◽  
...  
Keyword(s):  
Gravitational Field ◽  
Extra Dimension ◽  
Big Bang ◽  
Space Time ◽  
Cosmological Models ◽  
The World ◽  
New Type ◽  
The Big Bang ◽  
Insight Into ◽  
Classical Tests Of Relativity

We unify the gravitational field with its source by considering a new type of 5D manifold in which space and time are augmented by an extra dimension which induces 4D matter. The classical tests of relativity are satisfied, and for solitons we obtain new effects which can be tested astrophysically. The canonical cosmological models are in agreement with observations, and we gain new insight into the nature of the big bang. Our inference is that the world may be pure geometry in 5D.

scholarly journals HIGHER DIMENSIONAL SZEKERES' SPACE–TIME IN BRANS–DICKE SCALAR TENSOR THEORY

2004 ◽  
Vol 13 (06) ◽  
pp. 1073-1083
Author(s):  
ASIT BANERJEE ◽  
UJJAL DEBNATH ◽  
SUBENOY CHAKRABORTY
Keyword(s):  
Turning Point ◽  
Coupling Parameter ◽  
Big Bang ◽  
Space Time ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Tensor Theory ◽  
Higher Dimensional ◽  
Theory Of Gravitation ◽  
The Big Bang

The generalized Szekeres family of solution for quasi-spherical space–time of higher dimensions are obtained in the scalar tensor theory of gravitation. Brans–Dicke field equations expressed in Dicke's revised units are exhaustively solved for all the subfamilies of the said family. A particular group of solutions may also be interpreted as due to the presence of the so-called C-field of Hoyle and Narlikar and for a chosen sign of the coupling parameter. The models show either expansion from a big bang type of singularity or a collapse with the turning point at a lower bound. There is one particular case which starts from the big bang, reaches a maximum and collapses with the in course of time to a crunch.

scholarly journals Einstein's equations and a cosmology with finite matter

2015 ◽  
Vol 30 (13) ◽  
pp. 1550068
Author(s):  
L. Clavelli ◽  
Gary R. Goldstein
Keyword(s):  
Infinite Number ◽  
Total Mass ◽  
Delta Function ◽  
Big Bang ◽  
Space Time ◽  
Matter Density ◽  
Einstein’S Equations ◽  
Einstein's Equations ◽  
The Big Bang

We discuss various space–time metrics which are compatible with Einstein's equations and a previously suggested cosmology with a finite total mass.1 In this alternative cosmology, the matter density was postulated to be a spatial delta function at the time of the big bang thereafter diffusing outward with constant total mass. This proposal explores a departure from standard assumptions that the big bang occurred everywhere at once or was just one of an infinite number of previous and later transitions.

scholarly journals Harmonic cosmology: how much can we know about a universe before the big bang?

2008 ◽  
Vol 464 (2096) ◽  
pp. 2135-2150 ◽  
Author(s):  
Martin Bojowald
Keyword(s):  
Solvable Model ◽  
Quantum Fluctuations ◽  
Realistic Model ◽  
Big Bang ◽  
Exactly Solvable Model ◽  
Reliable Determination ◽  
Exactly Solvable ◽  
Time Singularities ◽  
The Big Bang

Quantum gravity may remove classical space–time singularities and thus reveal what a universe at the big bang could be like. In loop quantum cosmology, an exactly solvable model is available, which allows one to address precise dynamical coherent states and their evolution in such a setting. It is shown here that quantum fluctuations before the big bang are generically unrelated to those after the big bang. While this is derived only in the solvable model, it presents the case of the strongest control on coherence properties; adding ingredients to a realistic model could only increase the complexity. A reliable determination of pre-big bang quantum fluctuations of geometry would thus require exceedingly precise observations.

scholarly journals Theory of General Relativity: Historical Perspective

2015 ◽  
Vol 4 ◽  
pp. 49-52
Author(s):  
Ranjit Prasad Yadav
Keyword(s):  
General Relativity ◽  
Gravitational Force ◽  
Albert Einstein ◽  
Big Bang ◽  
Theory Of Relativity ◽  
General Theory Of Relativity ◽  
History Of ◽  
Big Bang Model ◽  
The Big Bang ◽  
Theories Of Gravitation

General relativity was developed by Albert Einstein near about 100 Years ago. This article attempt to give an outline about the brief history of general theory of relativity and to understand the background to the theory we have to look at how theories of gravitation developed. Before the advent of GR, Newton's law of gravitation had been accepted for more than two hundred years as a valid description of the gravitational force between masses i.e. gravity was the result of an attractive force between massive objects. General relativity has developed in to an essential tool in modern astrophysics. It provides the foundation for the understanding of black holes, regions of space where gravitational attraction is strong that not even light can escape and also a part of the big bang model of cosmology.DOI: http://dx.doi.org/10.3126/av.v4i0.12358Academic Voices Vol.4 2014: 49-52

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