operatorinduced

Operatorinduced (often hyphenated as operator-induced) is a term used in mathematics and related fields to describe structures, distances, or topologies that are defined by applying linear operators to elements of a space. It emphasizes that the construction derives from an operator rather than being intrinsic to the space itself.

In functional analysis, an operator-induced topology on a vector space X is the initial topology with respect to a family of linear maps {T_i: X -> Y_i}, where each Y_i is a normed or topological space. Equivalently, X carries the weakest topology that makes all T_i continuous. This yields a family of seminorms p_i(x) = ||T_i x||, with neighborhood bases generated by finite combinations of these seminorms. Common instances include the weak topology (induced by all continuous linear functionals) and the weak operator topology.

An operator-induced norm is a norm or seminorm on X generated by a single operator A: X -> Y, defined by ||x||_A = ||A x||_Y. If A is injective, ||·||_A is a norm; otherwise it is a seminorm with kernel equal to ker A. The operator norm of A itself, defined as sup_{||x||=1} ||A x||, is a standard measure of A’s action.

Operator-induced constructions are used to encode measurement, regularization, or constraints via an operator, capturing properties such as stability, continuity, or sparsity through how the operator acts on the space. The exact meaning is context-dependent, varying with the chosen operator or family of operators.