C.S. Unnikrishnan | |
---|---|
Born | Kalady, Keralam | 25 July 1962
Nationality | Indian |
Alma mater | Indian Institute of Technology, Madras Tata Institute of Fundamental Research University of Mumbai |
Occupation(s) | Professor, Tata Institute of Fundamental Research, India; Professor, Defence Institute of Advanced Technology, India; Adjunct Professor, Indian Institute of Astrophysics, India; |
Parent | C.K. Sivarama Pillai: G.Kalyanikutty Amma |
Awards | Breakthrough Prize in Physics (2016) Gruber Prize in Cosmology (2016) |
C. S. Unnikrishnan (born 25 July 1962) is an Indian physicist and professor known for his contributions in multiple areas of experimental and theoretical physics. He has been a professor at the Tata Institute of Fundamental Research [1] Mumbai and is currently a professor in the School of Quantum Technology at the Defence Institute of Advanced Technology [2] in Pune. He has made significant contributions in foundational issues in gravity [3] [4] [5] [6] [7] and quantum physics and has published over 250 research papers and articles. [8] [9] [10] Unnikrishnan is also a key member of the LIGO-India [11] [12] [13] [14] [15] project and a member of the global LIGO Scientific Collaboration [16] [17] [18]
Unnikrishnan received his M.Sc. degree from Indian Institute of Technology, Madras and his Ph.D. from the Tata Institute of Fundamental Research, University of Mumbai. He has also been a visiting researcher at the Kastler-Brossel Laboratory of the Ecole Normale Supérieure in Paris and at the University of Paris 13.
Unnikrishnan is a renowned researcher in the field of foundational issues in gravity [19] [20] [21] [17] and quantum physics, [22] including quantum optics. [23] His expertise lies in experimental physics, and he has been instrumental in setting up the laser-cooling laboratory at TIFR, [24] [25] Mumbai. He is well-versed in the use of torsion balances, [26] interferometers, [27] [28] laser cooled atoms, [29] and Bose-Einstein Condensates [30] for his experiments. [31]
Unnikrishnan's major theoretical contributions include the Theory of Cosmic Relativity [32] [33] [7] [34] and Universal Action Mechanics. These theories have provided new insights into our understanding of the interplay between gravity and quantum mechanics, and have opened up new avenues for further research. Cosmic Relativity, [35] replaces current theories of dynamics and relativity and argues that all relativistic phenomena and laws of dynamics are controlled by the gravitational potentials of matter and energy in the universe. [6] It provides evidence and solutions to several major issues in fundamental physics. [36]
The discovery of the quantization of the Hall effect, where the movement of electrons is restricted to a 2-D plane, was characterized by quantized plateaus in the Hall resistance and has a simple theory for the integer quantum Hall effect, [37] but there is still no proper understanding of the more spectacular fractional quantum Hall effect. [37] The Cosmic Relativity theory offers a comprehensive understanding of both integer and fractional effects by modifying the quantum degeneracy due to cosmic gravitomagnetic interaction. [38]
Awards
Unnikrishnan is a key member and proposer-scientist of the LIGO-India [39] project and has been a member of the LIGO Scientific Collaboration (LSC). [16] He has made a significant impact in the field of gravitational waves [40] [24] as he shared the Breakthrough Prize in Physics [41] and the Gruber Prize in Cosmology [42] with the LSC in 2016 for their groundbreaking discovery.
He has held academic positions at the Tata Institute of Fundamental Research (TIFR) [1] Mumbai, India, School of Quantum Technology at the Defence Institute of Advanced Technology (DIAT) [2] Pune,India and Indian Institute of Astrophysics (IIA), Bangalore, India.
Unnikrishnan has published over 250 research papers and articles, and is also the author of two major works: [21] [20] his first monograph "Gravity's Time" [20] and a major treatise "New Relativity in the Gravitational Universe". [43] The treatise, which presents a new and innovative perspective on the foundational basis of relativity, [44] has had a major impact in the field. The latter book calls for a change in the foundational basis of relativity and provides a solution to outstanding questions and puzzles about dynamics and relativity.
Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description of the largest-scale structures and dynamics of the universe and allows study of fundamental questions about its origin, structure, evolution, and ultimate fate. Cosmology as a science originated with the Copernican principle, which implies that celestial bodies obey identical physical laws to those on Earth, and Newtonian mechanics, which first allowed those physical laws to be understood.
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General relativity generalises special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime. In particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of second order partial differential equations.
In theories of quantum gravity, the graviton is the hypothetical quantum of gravity, an elementary particle that mediates the force of gravitational interaction. There is no complete quantum field theory of gravitons due to an outstanding mathematical problem with renormalization in general relativity. In string theory, believed by some to be a consistent theory of quantum gravity, the graviton is a massless state of a fundamental string.
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 vicinity of black holes or similar compact astrophysical objects, such as neutron stars as well as in the early stages of the universe moments after the Big Bang.
In physics, gravity (from Latin gravitas 'weight') is a fundamental interaction which causes mutual attraction between all things that have mass. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the strong interaction, 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak interaction. As a result, it has no significant influence at the level of subatomic particles. However, gravity is the most significant interaction between objects at the macroscopic scale, and it determines the motion of planets, stars, galaxies, and even light.
The following is a timeline of gravitational physics and general relativity.
The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Two large observatories were built in the United States with the aim of detecting gravitational waves by laser interferometry. These observatories use mirrors spaced four kilometers apart which are capable of detecting a change of less than one ten-thousandth the charge diameter of a proton.
Kip Stephen Thorne is an American theoretical physicist known for his contributions in gravitational physics and astrophysics.
Cosmic strings are hypothetical 1-dimensional topological defects which may have formed during a symmetry-breaking phase transition in the early universe when the topology of the vacuum manifold associated to this symmetry breaking was not simply connected. Their existence was first contemplated by the theoretical physicist Tom Kibble in the 1970s.
Rainer "Rai" Weiss is a German-born American physicist, known for his contributions in gravitational physics and astrophysics. He is a professor of physics emeritus at MIT and an adjunct professor at LSU. He is best known for inventing the laser interferometric technique which is the basic operation of LIGO. He was Chair of the COBE Science Working Group.
General relativity is a theory of gravitation developed by Albert Einstein between 1907 and 1915. The theory of general relativity says that the observed gravitational effect between masses results from their warping of spacetime.
The Max Planck Institute for Gravitational Physics is a Max Planck Institute whose research is aimed at investigating Einstein's theory of relativity and beyond: Mathematics, quantum gravity, astrophysical relativity, and gravitational-wave astronomy. The institute was founded in 1995 and is located in the Potsdam Science Park in Golm, Potsdam and in Hannover where it closely collaborates with the Leibniz University Hannover. Both the Potsdam and the Hannover parts of the institute are organized in three research departments and host a number of independent research groups.
Thanu Padmanabhan was an Indian theoretical physicist and cosmologist whose research spanned a wide variety of topics in gravitation, structure formation in the universe and quantum gravity. He published nearly 300 papers and reviews in international journals and ten books in these areas. He made several contributions related to the analysis and modelling of dark energy in the universe and the interpretation of gravity as an emergent phenomenon. He was a Distinguished Professor at the Inter-University Centre for Astronomy and Astrophysics (IUCAA) at Pune, India.
Gravitational waves are waves of the intensity of gravity that are generated by the accelerated masses of binary stars and other motions of gravitating masses, and propagate as waves outward from their source at the speed of light. They were first proposed by Oliver Heaviside in 1893 and then later by Henri Poincaré in 1905 as the gravitational equivalent of electromagnetic waves.
Gravitational-wave astronomy is an emerging field of science, concerning the observations of gravitational waves to collect relatively unique data and make inferences about objects such as neutron stars and black holes, events such as supernovae, and processes including those of the early universe shortly after the Big Bang.
In particle physics and physical cosmology, Planck units are a system of units of measurement defined exclusively in terms of four universal physical constants: c, G, ħ, and kB. Expressing one of these physical constants in terms of Planck units yields a numerical value of 1. They are a system of natural units, defined using fundamental properties of nature rather than properties of a chosen prototype object. Originally proposed in 1899 by German physicist Max Planck, they are relevant in research on unified theories such as quantum gravity.
The first direct observation of gravitational waves was made on 14 September 2015 and was announced by the LIGO and Virgo collaborations on 11 February 2016. Previously, gravitational waves had been inferred only indirectly, via their effect on the timing of pulsars in binary star systems. The waveform, detected by both LIGO observatories, matched the predictions of general relativity for a gravitational wave emanating from the inward spiral and merger of a pair of black holes of around 36 and 29 solar masses and the subsequent "ringdown" of the single resulting black hole. The signal was named GW150914. It was also the first observation of a binary black hole merger, demonstrating both the existence of binary stellar-mass black hole systems and the fact that such mergers could occur within the current age of the universe.
Pankaj S. Joshi is an Indian astrophysicist and cosmologist whose research is mainly focused on areas of gravitational collapse and spacetime singularity. He has published more than 225 research papers in national and international journals, and books and monographs on the subject. Currently he is a Distinguished Professor of Physics, and founding director of the International Center for Space and Cosmology at Ahmedabad University.
Rana X. Adhikari is an American experimental physicist. He is a professor of physics at the California Institute of Technology (Caltech) and an associate faculty member of the International Centre for Theoretical Sciences of Tata Institute of Fundamental Research (ICTS-TIFR).