normed functional
81Measure of non-compactness — In functional analysis, two measures of non compactness are commonly used; these associate numbers to sets in such a way that compact sets all get the measure 0, and other sets get measures that are bigger according to how far they are removed… …
82Gelfand representation — In mathematics, the Gelfand representation in functional analysis (named after I. M. Gelfand) has two related meanings:* a way of representing commutative Banach algebras as algebras of continuous functions; * the fact that for commutative C*… …
83Sobolev space — In mathematics, a Sobolev space is a vector space of functions equipped with a norm that is a combination of Lp norms of the function itself as well as its derivatives up to a given order. The derivatives are understood in a suitable weak sense… …
84Neumann series — A Neumann series is a mathematical series of the form where T is an operator. Hence, Tn is a mathematical notation for n consecutive operations of the operator T. This generalizes the geometric series. The series is named after the mathematician… …
85Reflective subcategory — In mathematics, a subcategory A of a category B is said to be reflective in B when the inclusion functor from A to B has a left adjoint. This adjoint is sometimes called a reflector. Dually, A is said to be coreflective in B when the inclusion… …
86Fraňková-Helly selection theorem — In mathematics, the Fraňková Helly selection theorem is a generalisation of Helly s selection theorem for functions of bounded variation to the case of regulated functions. It was proved in 1991 by the Czech mathematician Dana… …
87Term test — In mathematics, the nth term test for divergence[1] is a simple test for the divergence of an infinite series: If or if the limit does not exist, then diverges. Many authors do not name this test or give it a shorter name.[2] Cont …
88Lions–Lax–Milgram theorem — In mathematics, the Lions ndash;Lax ndash;Milgram theorem (or simply Lions rsquo; theorem) is a result in functional analysis with applications in the study of partial differential equations. It is a generalization of the famous Lax Milgram… …
89Continuous function — Topics in Calculus Fundamental theorem Limits of functions Continuity Mean value theorem Differential calculus  Derivative Change of variables Implicit differentiation Taylor s theorem Related rates …
90Topological space — Topological spaces are mathematical structures that allow the formal definition of concepts such as convergence, connectedness, and continuity. They appear in virtually every branch of modern mathematics and are a central unifying notion. The… …
