This is a collection of essays based on lectures that author has given on various occasions on foundation of quantum theory, symmetries and representation theory, and the quantum theory of the superworld created by physicists. The lectures are linked by a unifying theme: how the quantum world and superworld appear under the lens of symmetry and supersymmetry. In the world of ultra-small times and distances such as the Planck length and Planck time, physicists believe no measurements are possible and so the structure of spacetime itself is an unknown that has to be first understood. There have been suggestions (Volovich hypothesis) that world geometry at such energy regimes is non-archimedian and some of the lectures explore the consequences of such a hypothesis. Ultimately, symmetries and supersymmetries are described by the representation of groups and supergroups. The author's interest in representation is a lifelong one and evolved slowly, and owes a great deal to conversations and discussions he had with George Mackey and Harish-Chandra. The book concludes with a retrospective look at these conversations.
From the reviews:
"This volume is a marvelous collection of essays that marries the technical with the personal. The technical part is an exploration of symmetries that arise in considerations of quantum theory. The personal part consists of reminiscences by the author about his colleagues ... . Each essay provides a list of readings for those who wish to pursue the subject in greater depth." (William G. Faris, SIAM Review, Vol. 54 (1), 2012)
"Present book is an inspiring collection of essays and lectures the author has given at various places. ... The book has eight chapters containing many personal reflections. ... The book provides an impressively lucid presentation of the mentioned topics and will prove invaluable both to students as well as research workers in physics and mathematics." (Gert Roepstorff, Zentralblatt MATH, Vol. 1222, 2011)
"Varadarajan's Reflections on Quanta, Symmetries, and Supersymmetries is a wonderful collection of essays by a master of the genre ... presented in a compact fashion richly peppered with pithy personal remarks, both biographical and autobiographical. I dearly love Professor Varadarajan, and I am ecstatic at having a copy of this book all my own. Get a copy, too." (Michael Berg, The Mathematical Association of America, July, 2011)
"This volume is a marvelous collection of essays that marries the technical with the personal. The technical part is an exploration of symmetries that arise in considerations of quantum theory. The personal part consists of reminiscences by the author about his colleagues ... . Each essay provides a list of readings for those who wish to pursue the subject in greater depth." (William G. Faris, SIAM Review, Vol. 54 (1), 2012)
"Present book is an inspiring collection of essays and lectures the author has given at various places. ... The book has eight chapters containing many personal reflections. ... The book provides an impressively lucid presentation of the mentioned topics and will prove invaluable both to students as well as research workers in physics and mathematics." (Gert Roepstorff, Zentralblatt MATH, Vol. 1222, 2011)
"Varadarajan's Reflections on Quanta, Symmetries, and Supersymmetries is a wonderful collection of essays by a master of the genre ... presented in a compact fashion richly peppered with pithy personal remarks, both biographical and autobiographical. I dearly love Professor Varadarajan, and I am ecstatic at having a copy of this book all my own. Get a copy, too." (Michael Berg, The Mathematical Association of America, July, 2011)