The Story of Collapsing Stars
Title | The Story of Collapsing Stars PDF eBook |
Author | Pankaj S. Joshi |
Publisher | Oxford University Press, USA |
Pages | 241 |
Release | 2015 |
Genre | Nature |
ISBN | 0199686769 |
This book journeys into one of the most fascinating intellectual adventures of recent decades - understanding and exploring the final fate of massive collapsing stars in the universe. The issue is of great interest in fundamental physics and cosmology today, from both the perspective of gravitation theory and of modern astrophysical observations. This is a revolution in the making and may be intimately connected to our search for a unified understanding of the basic forces of nature, namely gravity that governs the cosmological universe, and the microscopic forces that include quantum phenomena. According to the general theory of relativity, a massive star that collapses catastrophically under its own gravity when it runs out of its internal nuclear fuel must give rise to a space-time singularity. Such singularities are regions in the universe where all physical quantities take their extreme values and become arbitrarily large. The singularities may be covered within a black hole, or visible to faraway observers in the universe. Thus, the final fate of a collapsing massive star is either a black hole or a visible naked singularity. We discuss here recent results and developments on the gravitational collapse of massive stars and possible observational implications when naked singularities happen in the universe. Large collapsing massive stars and the resulting space-time singularities may even provide a laboratory in the cosmos where one could test the unification possibilities of basic forces of nature.
Story of Collapsing Stars: Black Holes Naked Singularities & the Cosmic Play of Quantum Gravity
Title | Story of Collapsing Stars: Black Holes Naked Singularities & the Cosmic Play of Quantum Gravity PDF eBook |
Author | Pankaj S. Joshi |
Publisher | |
Pages | |
Release | 2018 |
Genre | |
ISBN |
The Story of Collapsing Stars
Title | The Story of Collapsing Stars PDF eBook |
Author | Pankaj S. Joshi |
Publisher | OUP Oxford |
Pages | 241 |
Release | 2015-01-08 |
Genre | Science |
ISBN | 0191510254 |
This book journeys into one of the most fascinating intellectual adventures of recent decades - understanding and exploring the final fate of massive collapsing stars in the universe. The issue is of great interest in fundamental physics and cosmology today, from both the perspective of gravitation theory and of modern astrophysical observations. This is a revolution in the making and may be intimately connected to our search for a unified understanding of the basic forces of nature, namely gravity that governs the cosmological universe, and the microscopic forces that include quantum phenomena. According to the general theory of relativity, a massive star that collapses catastrophically under its own gravity when it runs out of its internal nuclear fuel must give rise to a space-time singularity. Such singularities are regions in the universe where all physical quantities take their extreme values and become arbitrarily large. The singularities may be covered within a black hole, or visible to faraway observers in the universe. Thus, the final fate of a collapsing massive star is either a black hole or a visible naked singularity. We discuss here recent results and developments on the gravitational collapse of massive stars and possible observational implications when naked singularities happen in the universe. Large collapsing massive stars and the resulting space-time singularities may even provide a laboratory in the cosmos where one could test the unification possibilities of basic forces of nature.
Gravitational Collapse and Spacetime Singularities
Title | Gravitational Collapse and Spacetime Singularities PDF eBook |
Author | Pankaj S. Joshi |
Publisher | Cambridge University Press |
Pages | 284 |
Release | 2007-12-13 |
Genre | Science |
ISBN | 9780521871044 |
Physical phenomena in astrophysics and cosmology involve gravitational collapse in a fundamental way. The final fate of a massive star when it collapses under its own gravity at the end of its life cycle is one of the most important questions in gravitation theory and relativistic astrophysics, and is the foundation of black hole physics. General relativity predicts that continual gravitational collapse gives rise to a space-time singularity. Quantum gravity may take over in such regimes to resolve the classical space-time singularity. This book, first published in 2007, investigates these issues, and shows how the visible ultra-dense regions arise naturally and generically as an outcome of dynamical gravitational collapse. It will be of interest to graduate students and academic researchers in gravitation physics, fundamental physics, astrophysics, and cosmology. It includes a detailed review of research into gravitational collapse, and several examples of collapse models are investigated in detail.
Regular Black Holes
Title | Regular Black Holes PDF eBook |
Author | Cosimo Bambi |
Publisher | Springer Nature |
Pages | 505 |
Release | 2023-07-06 |
Genre | Science |
ISBN | 9819915961 |
Black holes are one of the most fascinating predictions of general relativity. They are the natural product of the complete gravitational collapse of matter and today we have a body of observational evidence supporting the existence of black holes in the Universe. However, general relativity predicts that at the center of black holes there are spacetime singularities, where predictability is lost and standard physics breaks down. It is widely believed that spacetime singularities are a symptom of the limitations of general relativity and must be solved within a theory of quantum gravity. Since we do not have yet any mature and reliable candidate for a quantum gravity theory, researchers have studied toy-models of singularity-free black holes and of singularity-free gravitational collapses in order to explore possible implications of the yet unknown theory of quantum gravity. This book reviews all main models of regular black holes and non-singular gravitational collapses proposed in the literature, and discuss the theoretical and observational implications of these scenarios.
Supermassive Black Hole
Title | Supermassive Black Hole PDF eBook |
Author | Celestial Angell |
Publisher | Dedona Publishing |
Pages | 43 |
Release | |
Genre | Science |
ISBN |
A black hole is a region in space where the gravitational pull is so strong that nothing, not even light, can escape from it. This occurs when a massive amount of matter is compressed into a very small area, creating a powerful gravitational field. Black holes form through various processes that involve the collapse of massive astronomical objects and the merging of smaller black holes. One primary method is the stellar collapse. Stars, during their lifecycle, fuse hydrogen into helium in their cores. When the hydrogen is depleted, they begin fusing heavier elements until iron is produced. For stars more than 20 times the mass of the Sun, the end of this fusion process leads to a supernova explosion. The core of the star collapses rapidly due to gravity, and if the core's mass is sufficiently large (typically more than about three times the mass of the Sun), it will continue collapsing into a singularity, forming a stellar-mass black hole. Another way black holes can form is through accretion and growth. A compact object like a neutron star or a white dwarf can accumulate matter from a companion star or its surroundings. As this matter accumulates, the mass of the compact object increases, and it may eventually reach a critical mass where it collapses into a black hole.
The Rise and Fall of the Black Hole Paradigm
Title | The Rise and Fall of the Black Hole Paradigm PDF eBook |
Author | Abhas Mitra |
Publisher | Pan Macmillan |
Pages | 230 |
Release | 2021-01-22 |
Genre | Science |
ISBN | 9389104157 |
Black holes have turned out to be the cornerstone of both physics and popular belief. But what if we were to realize that exact black holes cannot exist, even though their existence is apparently suggested by exact general relativistic solutions, and Roger Penrose won the 2020 Nobel Prize in Physics ‘for the discovery that black hole formation is a robust prediction of the general theory of relativity’? While it might seem far-fetched to claim so, it will be worth remembering that the finest theoretical physicists like Albert Einstein and Paul Dirac did not believe in black holes, and Stephen Hawking finally thought that there are no exact black holes. While the black hole paradigm has become commonplace in popular consciousness, in the last decade, noise has consistently grown about the many physical effects which can inhibit the formation of exact mathematical black holes. In The Rise and Fall of the Black Hole Paradigm, Abhas Mitra shows us how, much before these developments, he had proven why the so-called black holes must only be black hole pretenders. He identified these black hole candidates to be Magnetospheric Eternally Collapsing Objects (MECOs) and, along with Darryl J. Leiter and Stanley L. Robertson, generalized them. Recent evidence for the existence of strong magnetic fields around so-called black holes may provide confirmations of his claim.