The Indian Institute of Technology Bombay is organising an Institute lecture on March 14, 2023.

The details of the lecture are given below:

Title: "The Accelerating Expanding Universe: Dark Matter, Dark Energy, And Einstein's Cosmological Constant"

Speaker: Dr. Bharat Ratra, Distinguished Professor of Physics, Kansas State University, USA.

About the speaker: Dr. Bharat Ratra of Kansas State University is a physical cosmology theorist investigating dark energy and dark matter that constitutes 95% of the universe's current energy budget. His 1988 discovery, alongside Dr. Jim Peebles of Princeton University, of dynamical dark energy models launched him on a three decade+ quest to evaluate dark energy models using observational data. The remarkable enhancements in the quality and quantity of observational data over the past decade suggest that this process might be reaching its conclusion. In addition, he has studied the generation, evolution, and consequences of a large-scale cosmological magnetic field, as well as used novel techniques to analyze large data sets to derive accurate measurements of cosmological parameters such as the Hubble constant. His research has the potential to transform how cosmology is understood.

The implications of Dr. Ratra's research on dark energy are revolutionary within the field of physics. A more complete understanding of dark energy and dark matter will result in a 20-fold increase in the understood contributors to the current energy budget of our universe, an unprecedented increase in the modern era. In addition, the discovery of accelerated cosmological expansion in the late 1990s, which strongly suggests the need to improve either quantum mechanics or general relativity or perhaps both, will likely mark the beginning of yet another paradigm-shifting revolution in physics. Dr. Ratra has authored more than 140 scholarly works cited over 20,000 times in the scientific literature. As a theorist with more experience working with data than most theorists, Dr. Ratra has a specialization that has enabled him to make fascinating discoveries.

Abstract: Dark energy is the leading candidate for the mechanism that is responsible for causing the cosmological expansion to accelerate. Bharat Ratra will describe the astronomical data which persuade cosmologists that (as yet undetected) dark energy and dark matter are by far the main components of the energy budget of the universe at the present time. He will review how these observations have led to the development of a quantitative "standard" model of cosmology that describes the evolution of the universe from an early epoch of inflation to the complex hierarchy of structure seen today. In this non-technical talk, he will also discuss the basic physics, and the history of ideas, on which this model is based.