The Accelerating Expanding Universe: Dark Matter, Dark Energy, and Einstein's Cosmological Constant
Thursday, September 12, 2024
12:30 pm – 1:45 pm
Hixson-Lied Science Building, Room G-59
Abstract
Dark energy is the leading candidate for the mechanism that is responsible for causing the cosmological expansion to accelerate. Dr. 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.
Guest Speaker
Dr. Bharat Ratra, is a Distinguished Professor of Physics at Kansas State University. He works in the areas of cosmology and astroparticle physics, and he researches the structure and evolution of the universe. Two of his current principal interests are developing models for the large-scale matter and radiation distributions in the universe and testing these models by comparing predictions to observational data.
In 1988, Ratra and Jim Peebles proposed the first dynamical dark energy model. Dark energy is the leading candidate for the mechanism that is responsible for causing cosmological expansion to accelerate. The discovery that cosmological expansion is accelerating is one of the most significant scientific discoveries of the last quarter of a century.