A Review on Black Holes

In this study a quick summary for the back-hole theory was presented. It was presented earlier in from of graduation project at university of Bahri, college of applied and industrial sciences department of physics, Khartoum, Sudan by the second author and under supervision of the first author Black holes were once a star shining for years, before eventually collapse on their core forming the BH. There are three cases for a star non stable end is either a white dwarf, a neutron star or a black hole which is completely depend on the mass of the previous star which are called a compact star due to their highly condensation states. In this paper a quick summary for the theory was presented.

Lecture Notes in Physics, 2003

Our understanding of space and time is probed to its depths by black holes. These objects, which appear as a natural consequence of general relativity, provide a powerful analytical tool able to examine macroscopic and microscopic properties of the universe. This introductory article presents in a pictorial way the basic concepts of black hole's theory, as well as a description of the astronomical sites where black holes are suspected to lie, namely binary X-ray sources and galactic nuclei.

As a star grows old, swells, then collapses on itself, often you will hear the word " black hole " thrown around. The black hole is a gravitationally collapsed mass, from which no light, matter, or signal of any kind can escape. These exotic objects have captured our imagination ever since they were predicted by Einstein's Theory of General Relativity in 1915. So what exactly is a black hole? A black hole is what remains when a massive star dies. Not every star will become a black hole, only a select few with extremely large masses. In order to have the ability to become a black hole, a star will have to have about 20 times the mass of our Sun. No known process currently active in the universe can form black holes of less than stellar mass. This is because all present black hole formation is through gravitational collapse, and the smallest mass which can collapse to form a black hole produces a hole approximately 1.5-3.0 times the mass of the sun .Smaller masses collapse to form white dwarf stars or neutron stars.

Eprint Arxiv 0805 2082, 2008

Black holes are perhaps the most strange and fascinating objects known to exist in the universe. Our understanding of space and time is pushed to its limits by the extreme conditions found in these objects. They can be used as natural laboratories to test the behavior of matter in very strong gravitational fields. Black holes seem to play a key role in the universe, powering a wide variety of phenomena, from X-ray binaries to active galactic nuclei. In this article we will review the basics of black hole physics.

International Journal of Advance Research, Ideas and Innovations in Technology, 2018

A Black hole is a region of space from which nothing, including light, can escape. According to the general theory of relativity, it is the result of the curving of space-time caused by being composed of dense mass. Around a black hole, there is a position of no return, called the event horizon. Stellar black holes are made when the center of the very big star falls in upon itself, or collapses. When this happens, it causes a supernova. A supernova is an exploding star that blasts part of the star into space. Scientists think supermassive black holes were made at the same time as the galaxy they are in. Around a black hole, there is a position of no return, called the event horizon. It is called “Black” because it absorbs all the light that hits it, reflecting nothing, just like a perfect black body in thermodynamics. The name also said to be taken from the black hole incidence happened in Calcutta. Under the theory of quantum mechanics black holes have a temperature and emit Hawkin...

Resumen / Los agujeros negros son objetos totalmente colapsados en su campo gravitacional. Han sido estudia-dos teóricamente durante más de cuarenta años utilizando la teoría de la relatividad general. Más recientemente, se los ha investigado en el marco de teorías alternativas de la gravitación. En este artículo repasaré las principales propiedades de los agujeros negros y discutiré en forma accesible algunas controversias teóricas recientes sobre su naturaleza. Abstract / Black holes are fully gravitational collapsed objects. They have been studied from a theoretical point of view during more than 40 years using the theory of General Relativity. Recently they have been also investigated in the context of alternative theories of gravitation. In this paper I review the main properties of black holes and I discuss, in an accesible way, some recent controversies about the nature of these objects.

arXiv (Cornell University), 2015

The fourth chapter of the collection of problems in cosmology, devoted to black holes. Consists of basic introduction, sections on Schwarzschild and Kerr black holes, a section on particles' motion and collisions in general black hole space-times, and the astrophysical part. This version contains only formulations of 137 problems. The full collection, with solutions included, is available in the form of a wiki-based resource at www.universeinproblems.com. The cosmological community is welcome to contribute to its development.

1997

S. Chandrasekhar wrote in the prologue to his book on black holes, "The black holes of nature are the most perfect macroscopic objects there are in the universe: the only elements in their construction are our concepts of space and time." In this contribution I briefly discuss recent developments in fundamental theory and black holes that vindicate this statement in a modern perspective. I also include some of my reminiscences of Chandra.

2006