Samir Dayal Mathur is a

theoretical physicist Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experim ...

who specializes in string theory and

black hole A black hole is a region of spacetime where gravity is so strong that nothing, including light or other electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts that a sufficiently compact mass can defo ...

physics. Mathur is a professor in the Department of Physics at

Ohio State University The Ohio State University, commonly called Ohio State or OSU, is a public land-grant research university in Columbus, Ohio. A member of the University System of Ohio, it has been ranked by major institutional rankings among the best pu ...

and a member of the University's High Energy Theory Group. He was a faculty member at

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a Private university, private Land-grant university, land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern t ...

from 1991–99 and held postdoctoral positions at

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...

and the

Tata Institute of Fundamental Research Tata Institute of Fundamental Research (TIFR) is a public deemed research university located in Mumbai, India that is dedicated to basic research in mathematics and the sciences. It is a Deemed University and works under the umbrella of the De ...

. Mathur's research is focused on string theory, black holes, the

AdS/CFT In theoretical physics, the anti-de Sitter/conformal field theory correspondence, sometimes called Maldacena duality or gauge/gravity duality, is a conjectured relationship between two kinds of physical theories. On one side are anti-de Sitter ...

correspondence, and

cosmology Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', and in 1731 taken up in Latin by German philosophe ...

. He is best known for developing the

Fuzzball Fuzzball may refer to: * Fuzzball (sport), a variation of baseball similar to stickball * Fuzzball (string theory), an alternative quantum description of black holes * Fuzzball router, the first modern routers on the Internet * ''Fuzzball'', a car ...

conjecture as a resolution of the

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 wh ...

. The Fuzzball conjecture asserts that the fundamental description of black holes is given by a quantum

bound state Bound or bounds may refer to: Mathematics * Bound variable * Upper and lower bounds, observed limits of mathematical functions Physics * Bound state, a particle that has a tendency to remain localized in one or more regions of space Geography * ...

of matter which has the same size as the corresponding classical black hole. This quantum bound state replaces the

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 ob ...

and singularity, and the classical black hole metric is claimed to be an approximate effective description. In 2009 Mathur published a strong version of the black hole information paradox, strengthening Stephen Hawking's original version by demonstrating that small local corrections to Hawking's semiclassical analysis cannot restore

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 quantu ...

. This result was obtained by applying

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 thre ...

to the evaporation of

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 ar ...

. This led to a renewed interest in the information paradox and the development of the 2012 black hole firewall paradox.

References

External links

Mathur's web page at The Ohio State University

List of Publications on INSPIRE-HEP

— by The Ohio State University
KITP Seminar: The Black Hole Story in 4 Steps , Samir Mathur
Living people 20th-century Indian physicists Ohio State University faculty Indian string theorists Year of birth missing (living people) MIT Center for Theoretical Physics faculty {{physicist-stub