Abhay Vasant Ashtekar (born 5 July 1949) is an Indian theoretical physicist. He is the Eberly Professor of Physics and the Director of the Institute for Gravitational Physics and Geometry at

Pennsylvania State University The Pennsylvania State University (Penn State or PSU) is a Public university, public Commonwealth System of Higher Education, state-related Land-grant university, land-grant research university with campuses and facilities throughout Pennsylvan ...

. As the creator of

Ashtekar variables In the ADM formulation of general relativity, spacetime is split into spatial slices and a time axis. The basic variables are taken to be the induced metric q_ (x) on the spatial slice and the metric's conjugate momentum K^ (x), which is related ...

, he is one of the founders of

loop quantum gravity Loop quantum gravity (LQG) is a theory of quantum gravity, which aims to merge quantum mechanics and general relativity, incorporating matter of the Standard Model into the framework established for the pure quantum gravity case. It is an attem ...

and its subfield

loop quantum cosmology Loop quantum cosmology (LQC) is a finite, symmetry-reduced model of loop quantum gravity ( LQG) that predicts a "quantum bridge" between contracting and expanding cosmological branches. The distinguishing feature of LQC is the prominent role playe ...

. He has also written a number of descriptions of loop quantum gravity that are accessible to non-physicists. In 1999, Ashtekar and his colleagues were able to calculate the

entropy Entropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynam ...

for a

black hole A black hole is a region of spacetime where gravitation, gravity is so strong that nothing, including light or other Electromagnetic radiation, electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts t ...

, matching a legendary 1974 prediction by

Hawking Hawking may refer to: People * Stephen Hawking (1942–2018), English theoretical physicist and cosmologist *Hawking (surname), a family name (including a list of other persons with the name) Film * ''Hawking'' (2004 film), about Stephen Haw ...

. Oxford mathematical physicist

Roger Penrose Sir Roger Penrose (born 8 August 1931) is an English mathematician, mathematical physicist, philosopher of science and Nobel Laureate in Physics. He is Emeritus Rouse Ball Professor of Mathematics in the University of Oxford, an emeritus fello ...

has described Ashtekar's approach to

quantum gravity Quantum gravity (QG) is a field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics; it deals with environments in which neither gravitational nor quantum effects can be ignored, such as in the vi ...

as "The most important of all the attempts at 'quantizing' general relativity." Ashtekar was elected as Member to National Academy of Sciences in May 2016.

Biography

Abhay Ashtekar grew up in several cities, including

Mumbai Mumbai (, ; also known as Bombay — the official name until 1995) is the capital city of the Indian state of Maharashtra and the ''de facto'' financial centre of India. According to the United Nations, as of 2018, Mumbai is the second- ...

, in the state of

Maharashtra Maharashtra (; , abbr. MH or Maha) is a states and union territories of India, state in the western India, western peninsular region of India occupying a substantial portion of the Deccan Plateau. Maharashtra is the List of states and union te ...

, India. After completing his undergraduate education in India, Ashtekar enrolled in the graduate program for

gravitation In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stron ...

at the

University of Texas at Austin The University of Texas at Austin (UT Austin, UT, or Texas) is a public research university in Austin, Texas. It was founded in 1883 and is the oldest institution in the University of Texas System. With 40,916 undergraduate students, 11,075 ...

. He went on to complete his

PhD PHD or PhD may refer to: * Doctor of Philosophy (PhD), an academic qualification Entertainment * '' PhD: Phantasy Degree'', a Korean comic series * ''Piled Higher and Deeper'', a web comic * Ph.D. (band), a 1980s British group ** Ph.D. (Ph.D. albu ...

at the

University of Chicago The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park neighborhood. The University of Chicago is consistently ranked among the b ...

under the supervision of

Robert Geroch Robert Geroch (born 1 June 1942 in Akron, Ohio) is an American theoretical physicist and professor at the University of Chicago. He has worked prominently on general relativity and mathematical physics and has promoted the use of category theory i ...

in 1978 and held several appointments at

Oxford Oxford () is a city in England. It is the county town and only city of Oxfordshire. In 2020, its population was estimated at 151,584. It is north-west of London, south-east of Birmingham and north-east of Bristol. The city is home to the ...

Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...

Syracuse Syracuse may refer to: Places Italy *Syracuse, Sicily, or spelled as ''Siracusa'' *Province of Syracuse United States *Syracuse, New York **East Syracuse, New York **North Syracuse, New York *Syracuse, Indiana * Syracuse, Kansas *Syracuse, Miss ...

before settling at

Penn State #Redirect Pennsylvania State University The Pennsylvania State University (Penn State or PSU) is a Public university, public Commonwealth System of Higher Education, state-related Land-grant university, land-grant research university with campu ...

. He married Christine Clarke in 1986 and the two have a son, Neil Ashtekar.

Religious views

Abhay Ashtekar is an

atheist Atheism, in the broadest sense, is an absence of belief in the existence of deities. Less broadly, atheism is a rejection of the belief that any deities exist. In an even narrower sense, atheism is specifically the position that there no ...

, though he enjoys reading on Indian and other eastern philosophy, namely the

Tao ''Tao'' or ''Dao'' is the natural order of the universe, whose character one's intuition must discern to realize the potential for individual wisdom, as conceived in the context of East Asian philosophy, East Asian religions, or any other philo ...

and the

Zen Zen ( zh, t=禪, p=Chán; ja, text= 禅, translit=zen; ko, text=선, translit=Seon; vi, text=Thiền) is a school of Mahayana Buddhism that originated in China during the Tang dynasty, known as the Chan School (''Chánzong'' 禪宗), and ...

traditions. Furthermore, he believes to be inspired from the

Bhagavad Gita The Bhagavad Gita (; sa, श्रीमद्भगवद्गीता, lit=The Song by God, translit=śrīmadbhagavadgītā;), often referred to as the Gita (), is a 700- verse Hindu scripture that is part of the epic ''Mahabharata'' (c ...

as regards his attitude towards work.

Books

# A. Magnon and A. Ashtekar, Translation from French of Élie Cartan's work, "Sur les variétés à connexion affine et la théorie de la relativité généralisée" with a commentary and foreword by A. Trautman, Bibliopolis, Naples, 1986, 199 pages. # A. Ashtekar, Asymptotic Quantization. Bibliopolis, Naples, 1987, 107 pages. # A. Ashtekar, (with invited contributions) New Perspectives in Canonical Gravity. Bibliopolis, Naples, 1988, 324 pages. # A. Ashtekar and J. Stachel, Editors; Conceptual Problems of Quantum Gravity. Proceedings of the 1988 Osgood Hill Conference (Birkhauser, N. Y., 1991), 602 pages. # A. Ashtekar, Lectures on Non-perturbative Canonical Gravity, (Notes prepared in collaboration with R.S. Tate), (World Scientific Singapore, 1991), 334 pages. # A. Ashtekar, R.C. Cohen, D. Howard, J. Renn, S. Sarkar and A. Shimony (Editors), Revisiting the Foundations of Relativistic Physics, Festschrift in honor of John Stachel, Boston Studies in Philosophy of Science, Volume 234, (Kluwer Academic, 2003).

References

External links

Oral History interview transcript for Abhay Ashtekar on 3 February 2021, American Institute of Physics, Niels Bohr Library and Archives
*

Ashtekar's publication
on

ArXiv arXiv (pronounced "archive"—the X represents the Greek letter chi ⟨χ⟩) is an open-access repository of electronic preprints and postprints (known as e-prints) approved for posting after moderation, but not peer review. It consists of ...

{{DEFAULTSORT:Ashtekar, Abhay 20th-century Indian physicists American relativity theorists Loop quantum gravity researchers 1949 births Living people University of Chicago alumni Pennsylvania State University faculty American atheists Indian atheists Indian emigrants to the United States Members of the United States National Academy of Sciences American academics of Indian descent People from Kolhapur Syracuse University faculty Scientists from Maharashtra Indian American mr:अभय अष्टेकर

Biography

Religious views

Books

See also

References

External links