irregularities of distribution - Incidence correspondence - Incompressible mapping - Index of an operator - Interior function - Irregular linear system - Isochronous differential equation - Isotypic component - Iwasawa manifold - Iwasawa theorem - Indecomposable quotient - Integralilty preserving homomorphism - Index of a Weyl group element - Indivisible root - Mackey-Shoda criteria for induced representations - Inductive tensor product - Inductive topology - Inequalities of descent - Infinitesimal character - Infinitesimal equivalence - Infinitesimally unitary - Inhomogeneous Lorentz group - Integrable unitary representation - Intertwining form - Intertwining number theorem - Invariant integral - Irreducible root system - Isotypic submodule - Impulsive coordinate -