Usha Raut, Ph.D.

Ph.D.

Physics

Indian Institute of Science

1985

M.S.

Physics

Indian Institute of Science

1981

B.S.

Physics

Indian Institute of Science

1980

Albert Nelson Marquis Lifetime Achievement Award by Marquis Who's Who

2018

Marquis’ Who’s Who in American Physics

2010 - present

Sigma Pi Sigma Award and Medal for High Scholarship in Physics

1996

Faculty Grant

University of Wisconsin – Stout, Denver, CO

2009

Faculty Research and Endeavors Grant

Liege, Belgium, Sweden

1986

Hydrodynamic Analogue for Curved Space-Time and General Relativity

Cipolla, J., Raut, U.

2014

An attempt is made to simulate the curved space-time of General Relativity by comparison with the characteristics of a potential vortex at steady state sometimes called a free vortex. In this paper, we present results of our study of the potential vortex as an analogy with gravity and General Relativity. Analyses of potential vortex characteristics demonstrate that an analogy exists between potential vortex flow, General Relativity and the gravitational fields around massive objects. An analogue model of gravity is developed which simulates the potential vortex model of space-time observed by Gravity Probe-B experiments. Statements by Gravity Probe-B researchers that the region around Earth resembles a “space-time vortex” lend credibility to the premise of this paper that potential vortex flow and gravity are related. Albert Einstein introduced the first analogue model for General Relativity that describes space-time as a membrane upon which objects move along geodesics. Analogue models provide a unique and viable means of analyzing complex space-time in situations that would normally be beyond our means to explore using conventional methods. Further, by exploring the dynamics of the analogue model, we are able to recover the equivalent form of the Einstein field equation starting from the usual equations of hydrodynamics and vector dynamics and make predictions about space-time and gravity using these observations. An implication for the existence of an analogy between space-time and the potential vortex is the possibility that space-time can be considered a superfluid forming the surface of our universe.

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MOND using a probabilistic approach

Raut, U.

2009

MOND has been proposed as a viable alternative to the dark matter hypothesis. In the original MOND formulation [1], a modification of Newtonian Dynamics was brought about by postulating new equations of particle motion at extremely low accelerations, as a possible explanation for the flat rotation curves of spiral galaxies. In this paper, we attempt a different approach to modify the usual force laws by trying to link gravity with the probabilistic aspects of quantum mechanics [2]. In order to achieve this, one starts by replacing the classical notion of a continuous distance between two elementary particles with a statistical probability function, pi. The gravitational force between two elementary particles then can be interpreted in terms of the probability of interaction between them. We attempt to show that such a modified gravitational force would fall off a lot slower than the usual inverse square law predicts, leading to revised MOND equations. In the limit that the statistical aggregate of the probabilities becomes equal to the usual inverse square law force, we recover Newtonian/Einstein gravity.

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