Small representations of a group bring us to large symmetries in a
representation space. Analysis on minimal representations utilises large
symmetries in their geometric models, and serves as a driving force in creating
new interesting problems that interact with other branches of mathematics.
This article discusses the following three topics that arise from minimal
representations of the indefinite orthogonal group:
1. construction of conservative quantities for ultra-hyperbolic equations,
2. quantative discrete branching laws,
3. deformation of the Fourier transform with emphasis on the prominent roles
of Sato's idea on algebraic analysis.Comment: Special Volume for Mikio Sato in celebration of fifty years of
algebraic analysi