In the spirit of Alladi Ramakrishnans profound interest and contributions to three fields of science Mathematics, Statistics, and Physics this volume contains invited surveys and research articles from prominent members of these communities who also knew Ramakrishnan personally and greatly respected his influence in these areas of science. Historical photos, telegrams, and biographical narratives of Alladi Ramakrishnans illustrious career of special interest are included as well.In the spirit of Alladi Ramakrishnans profound interest and contributions to three fields of science Mathematics, Statistics, and Physics this volume contains invited surveys and research articles from prominent members of these communities who also knew Ramakrishnan personally and greatly respected his influence in these areas of science.Alladi Ramakrishnan (19232008) was an eminent scientist who had a wide range of research interests in theoretical and mathematical physics. Professor Ramakrishnan made signi?cant contributions to probability and statistics, elem- tary particle physics, cosmic rays and astrophysics, matrix theory, and the special theory of relativity. Ramakrishnan believedstrongly that in addition to doing fun- mental research, one must contribute to the advancementof the profession. Inspired by his visit to the Institute for Advanced Study in Princeton in 19571958, he returned to Madras and began the Theoretical Physics Seminar at his family home Ekamra Nivas. These seminars were ultimately responsible for the creation of MATSCIENCE, The Institute of Mathematical Sciences in 1962. This institute, of which he was the Director for its ?rst 21years, has grown steadily in size and stature, and is his monumental contribution to the profession. In a distinguished scienti?c life that has spanned more than ?ve decades, Professor Ramakrishnan has come into close contact with, and was in?uenced by, several eminent mathema- cians and physicists, and has moulded the careerlS0