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 unkown 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.