Spacetime Singularities in General Relativity

2020 ◽  
pp. 1-17
Author(s):  
César A. Zen Vasconcellos
Keyword(s):  
General Relativity ◽  
Spacetime Singularities

scholarly journals Quantum Black Holes and (Re)Solution of the Singularity

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 478
Author(s):  
Roberto Casadio
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Quantum Theory ◽  
Quantum State ◽  
Spacetime Singularities ◽  
Classical General Relativity ◽  
Spacetime Geometry ◽  
Complete Quantum ◽  
General Conditions

Classical general relativity predicts the occurrence of spacetime singularities under very general conditions. Starting from the idea that the spacetime geometry must be described by suitable states in the complete quantum theory of matter and gravity, we shall argue that this scenario cannot be realised physically since no proper quantum state may contain the infinite momentum modes required to resolve the singularity.

Introduction

2017 ◽  
Author(s):  
Hanoch Gutfreund ◽  
Jürgen Renn
Keyword(s):  
General Relativity ◽  
Golden Age ◽  
Spacetime Singularities ◽  
Community Building ◽  
Observational Cosmology ◽  
Formative Years

This introductory chapter provides a brief background into the development of Albert Einstein's special and general theories of relativity. As a characteristic stage in the development of the theory, the chapter focuses on the formative years which have, remarkably, received less attention from historians than subsequent periods. It argues that a “renaissance” of general relativity had begun essentially as the result of a community-building effort turning the theory into a universally applicable framework. This revival was followed by what has been called the “golden age” of relativity, which witnessed new conceptual insights, such as those into the nature of spacetime singularities, and turned the theory into the foundation of modern astrophysics and observational cosmology.

scholarly journals Vacuum Semiclassical Gravity Does Not Leave Space for Safe Singularities

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 281
Author(s):  
Julio Arrechea ◽  
Carlos Barceló ◽  
Valentin Boyanov ◽  
Luis J. Garay
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Gravitational Collapse ◽  
Spacetime Singularities ◽  
Cosmic Censorship ◽  
Semiclassical Gravity ◽  
Strong Cosmic Censorship

General relativity predicts its own demise at singularities but also appears to conveniently shield itself from the catastrophic consequences of such singularities, making them safe. For instance, if strong cosmic censorship were ultimately satisfied, spacetime singularities, although present, would not pose any practical problems to predictability. Here, we argue that under semiclassical effects, the situation should be rather different: the potential singularities which could appear in the theory will generically affect predictability, and so one will be forced to analyse whether there is a way to regularise them. For these possible regularisations, the presence and behaviour of matter during gravitational collapse and stabilisation into new structures will play a key role. First, we show that the static semiclassical counterparts to the Schwarzschild and Reissner–Nordström geometries have singularities which are no longer hidden behind horizons. Then, we argue that in dynamical scenarios of formation and evaporation of black holes, we are left with only three possible outcomes which could avoid singularities and eventual predictability issues. We briefly analyse the viability of each one of them within semiclassical gravity and discuss the expected characteristic timescales of their evolution.

scholarly journals COLLAPSING AND EXPANDING CYLINDRICALLY SYMMETRIC FIELDS WITH LIGHTLIKE WAVE-FRONTS IN GENERAL RELATIVITY

2002 ◽  
Vol 11 (04) ◽  
pp. 561-579 ◽  
Author(s):  
PAULO R. C. T. PEREIRA ◽  
A. Z. WANG
Keyword(s):  
General Relativity ◽  
Spacetime Singularities ◽  
Matter Field ◽  
Wave Fronts ◽  
Flat Spacetime ◽  
Cylindrically Symmetric ◽  
General Part ◽  
The Waves ◽  
Spacelike Infinity ◽  
Matter Fields

The dynamics of collapsing and expanding cylindrically symmetric gravitational and matter fields with lightlike wave-fronts is studied in General Relativity, using the Barrabés–Israel method. As an application of the general formulae developed, the collapse of a matter field that satisfies the condition RABgAB =0, (A,B = z, φ), in an otherwise flat spacetime background is studied. In particular, it is found that the gravitational collapse of a purely gravitational wave or a null dust fluid cannot be realized in a flat spacetime background. The studies are further specified to the collapse of purely gravitational waves and the general conditions for such collapse are found. It is shown that after the waves arrive at the axis, in general, part of them is reflected to spacelike infinity along the future light cone, and part of it is focused to form spacetime singularities on the symmetry axis. The cases where the collapse does not result in the formation of spacetime singularities are also identified.

General Relativity

2006 ◽  
Author(s):  
M. P. Hobson ◽  
G. P. Efstathiou ◽  
A. N. Lasenby
Keyword(s):  
General Relativity
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