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Samir D. Mathur
Samir Dayal Mathur is a theoretical physicist who specializes in string theory and black hole physics. Mathur is a professor in the Department of Physics at Ohio State University and a member of the University's High Energy Theory Group. He was a faculty member at Massachusetts Institute of Technology from 1991–99 and held postdoctoral positions at Harvard University and the Tata Institute of Fundamental Research. Mathur's research is focused on string theory, black holes, the AdS/CFT correspondence, and cosmology. He is best known for developing the Fuzzball conjecture as a resolution of the black hole information paradox. The Fuzzball conjecture asserts that the fundamental description of black holes is given by a quantum bound state of matter which has the same size as the corresponding classical black hole. This quantum bound state replaces the event horizon and singularity, and the classical black hole metric is claimed to be an approximate effective description. In 2009 M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karur
Karur () is a city in the Indian state of Tamil Nadu. Karur is the administrative headquarters of Karur district. It is located on the banks of River Amaravathi, Kaveri and Noyyal. Karur is well known for the export of Home Textile products to USA, UK, Australia, Europe and many more countries. It is situated at about 395 kilometers southwest of the state capital Chennai, 75 km from Tiruchirappalli, 120 km away from Coimbatore, 295 km away from Bengaluru and 300 km away from Kochi. Etymology Karur is mentioned in inscriptions and literature by two names, Karuvoor (the home of Karuvoor Devar) and Vanji. Additionally, it has been referred to as: Adipuram, Tiruaanilai, Paupatheechuram, Karuvaippatinam, Vanjularanyam, Garbhapuram, Thiru vithuvakkottam, Bhaskarapuram, Mudivazhangu Viracholapuram, Karapuram, Aadaga maadam, Cherama nagar and Shanmangala Kshetram. Among them, the name Adipuram, meaning the first city seems to indicate that it was held as the forem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Hole Information Paradox
The black hole information paradox is a puzzle that appears when the predictions of quantum mechanics and general relativity are combined. The theory of general relativity predicts the existence of black holes that are regions of spacetime from which nothing — not even light — can escape. In the 1970s, Stephen Hawking applied the rules of quantum mechanics to such systems and found that an isolated black hole would emit a form of radiation called Hawking radiation. Hawking also argued that the detailed form of the radiation would be independent of the initial state of the black hole and would depend only on its mass, electric charge and angular momentum. The information paradox appears when one considers a process in which a black hole is formed through a physical process and then evaporates away entirely through Hawking radiation. Hawking's calculation suggests that the final state of radiation would retain information only about the total mass, electric charge and angular m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian String Theorists
Indian or Indians may refer to: Peoples South Asia * Indian people, people of Indian nationality, or people who have an Indian ancestor ** Non-resident Indian, a citizen of India who has temporarily emigrated to another country * South Asian ethnic groups, referring to people of the Indian subcontinent, as well as the greater South Asia region prior to the 1947 partition of India * Anglo-Indians, people with mixed Indian and British ancestry, or people of British descent born or living in the Indian subcontinent * East Indians, a Christian community in India Europe * British Indians, British people of Indian origin The Americas * Indo-Canadians, Canadian people of Indian origin * Indian Americans, American people of Indian origin * Indigenous peoples of the Americas, the pre-Columbian inhabitants of the Americas and their descendants ** Plains Indians, the common name for the Native Americans who lived on the Great Plains of North America ** Native Americans in the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohio State University Faculty
Faculty may refer to: * Faculty (academic staff), the academic staff of a university (North American usage) * Faculty (division), a division within a university (usage outside of the United States) * Faculty (instrument), an instrument or warrant in canon law, especially a judicial or quasi-judicial warrant from an ecclesiastical court or tribunal * Faculty (company), a British artificial intelligence company * Aspects of intelligence ("cognitive faculties") * Senses of sight, hearing, touch, etc. ("perceptive faculties") * ''The Faculty'', a 1998 horror/sci-fi movie by Robert Rodriguez * The Faculty (TV series), ''The Faculty'' (TV series), a 1996 American sitcom * The rights of a priest to celebrate or perform various liturgical functions {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Living People
Related categories * :Year of birth missing (living people) / :Year of birth unknown * :Date of birth missing (living people) / :Date of birth unknown * :Place of birth missing (living people) / :Place of birth unknown * :Year of death missing / :Year of death unknown * :Date of death missing / :Date of death unknown * :Place of death missing / :Place of death unknown * :Missing middle or first names See also * :Dead people * :Template:L, which generates this category or death years, and birth year and sort keys. : {{DEFAULTSORT:Living people 21st-century people People by status ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firewall (physics)
A black hole firewall is a hypothetical phenomenon where an observer falling into a black hole encounters high-energy quanta at (or near) the event horizon. The "firewall" phenomenon was proposed in 2012 by physicists Ahmed Almheiri, Donald Marolf, Joseph Polchinski, and James Sully as a possible solution to an apparent inconsistency in black hole complementarity. The proposal is sometimes referred to as the AMPS firewall, an initialism for the names of the authors of the 2012 paper. The potential inconsistency pointed out by AMPS had been pointed out earlier by Samir Mathur who used the argument in favour of the fuzzball proposal. The use of a firewall to resolve this inconsistency remains controversial, with physicists divided as to the solution to the paradox. The motivating paradox According to quantum field theory in curved spacetime, a single emission of Hawking radiation involves two mutually entangled particles. The outgoing particle escapes and is emitted as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawking Radiation
Hawking radiation is theoretical black body radiation that is theorized to be released outside a black hole's event horizon because of relativistic quantum effects. It is named after the physicist Stephen Hawking, who developed a theoretical argument for its existence in 1974. Hawking radiation is a purely kinematic effect that is generic to Lorentzian geometries containing event horizons or local apparent horizons. Hawking radiation reduces the mass and rotational energy of black holes and is therefore also theorized to cause black hole evaporation. Because of this, black holes that do not gain mass through other means are expected to shrink and ultimately vanish. For all except the smallest black holes, this would happen extremely slowly. The radiation temperature is inversely proportional to the black hole's mass, so micro black holes are predicted to be larger emitters of radiation than larger black holes and should dissipate faster. Overview Black holes are astrophysica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strong Subadditivity Of Quantum Entropy
In quantum information theory, strong subadditivity of quantum entropy (SSA) is the relation among the von Neumann entropies of various quantum subsystems of a larger quantum system consisting of three subsystems (or of one quantum system with three degrees of freedom). It is a basic theorem in modern quantum information theory. It was conjectured by D. W. Robinson and D. Ruelle in 1966 and O. E. Lanford III and D. W. Robinson in 1968 and proved in 1973 by E.H. Lieb and M.B. Ruskai, building on results obtained by Lieb in his proof of the Wigner-Yanase-Dyson conjecture. The classical version of SSA was long known and appreciated in classical probability theory and information theory. The proof of this relation in the classical case is quite easy, but the quantum case is difficult because of the non-commutativity of the reduced density matrices describing the quantum subsystems. Some useful references here include: *"Quantum Computation and Quantum Information" *"Quantum Entr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unitarity
In quantum physics, unitarity is the condition that the time evolution of a quantum state according to the Schrödinger equation is mathematically represented by a unitary operator. This is typically taken as an axiom or basic postulate of quantum mechanics, while generalizations of or departures from unitarity are part of speculations about theories that may go beyond quantum mechanics. A unitarity bound is any inequality that follows from the unitarity of the evolution operator, i.e. from the statement that time evolution preserves inner products in Hilbert space. Hamiltonian evolution Time evolution described by a time-independent Hamiltonian is represented by a one-parameter family of unitary operators, for which the Hamiltonian is a generator: U(t) = e^. In the Schrödinger picture, the unitary operators are taken to act upon the system's quantum state, whereas in the Heisenberg picture, the time dependence is incorporated into the observables instead. Implications of unit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Event Horizon
In astrophysics, an event horizon is a boundary beyond which events cannot affect an observer. Wolfgang Rindler coined the term in the 1950s. In 1784, John Michell proposed that gravity can be strong enough in the vicinity of massive compact objects that even light cannot escape. At that time, the Newtonian theory of gravitation and the so-called corpuscular theory of light were dominant. In these theories, if the escape velocity of the gravitational influence of a massive object exceeds the speed of light, then light originating inside or from it can escape temporarily but will return. In 1958, David Finkelstein used general relativity to introduce a stricter definition of a local black hole event horizon as a boundary beyond which events of any kind cannot affect an outside observer, leading to information and firewall paradoxes, encouraging the re-examination of the concept of local event horizons and the notion of black holes. Several theories were subsequently developed, som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
