Mathematical Sciences 2009

“I think this Prize (Infosys Prize) will go a long way in • B.Sc. in Physics from Prof. Ashoke Sen is being recognized for his attracting young talent to science and that's what we Calcutta University important contributions to String Theory, which need to build a strong country…Whatever I've done is • M.Sc. in Physics from is a vital part of Mathematical Physics. Among built on the work of many others and my work should the Indian Institute of his contributions is his work on S‑duality that really be thought of as a tiny piece of a vast effort Technology, Kanpur established links between weak and strong coupling regimes of certain String Theories. that is going on, in trying to understand the basic • Ph.D. in Physics from the This made it possible to make inferences laws of nature.” State University of New York, concerning the behavior of the system in the Stonybrook strong coupling regime by a perturbative • Post doctoral research at analysis of the system in the weak coupling Ashoke Sen Fermilab, Batavia, and at regime. SLAC, Stanford Professor, Harish‑Chandra Research Institute, Allahabad

Unifying gravity and quantum mechanics

The theory suggested that these strings vibrate (known as ‘excitations’) and depending on how they vibrate they form different particles. Many advances have been made in proving String Theory. The string theories have Prof. Ashoke Sen's landmark Prof. Sen's research attempts For many years now, scientists been classified according to whether contribution to string theory to unify the theories of gravity have been trying to work out and quantum mechanics and to So, what was the nature of the strings are open or closed and has been his work on dualities. the composition of our universe. complete the task that Einstein particles and forces? Several are further classified according to the Sen has worked out a surprising They first discovered that the world had begun. His work on entropy theories came up, including allowed modes of vibration of the connection between weak and around us was made up of atoms function formalism has helped String Theory. According to string. At one time, string theorists strong coupling regimes of a String and these in turn were made up provide a statistical interpretation this theory all particles and believed that each of the string Theory. Coupling regimes refer to of even tinier particles such as of Bekenstein‑Hawking entropy forms of energy are arranged theories were distinct and could exist the strength of interaction in string electrons, protons, neutrons, quarks of black holes. He has also made in the form of strings. These without the other. Soon they realized theories. The coupling constants in and others. These particles interact other important contributions hypothetical strings had only that these theories are connected to the string theories are controlled via four different types of forces. to String Theory, including the the dimension of length. each other and these connections by particular oscillation modes of These are gravity, electromagnetism, came to be known as ‘dualities’. the string called dilatons and they construction and study of time weak nuclear forces and strong exhibit symmetry, which is called dependent solutions that has nuclear forces. S‑duality. led to cosmological models.

26 | Celebrating 5 years – Infosys Science Foundation