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In mathematics, a linear map is a mapping between two modules (including vector spaces) that preserves the operations of addition and scalar multiplication. By studying the linear maps between two modules one can gain insight into their structures. If the modules have additional structure, like topologies or bornologies, then one can study the subspace of linear maps that preserve this structure. ==Topologies of uniform convergence== Suppose that ''T'' be any set and that be collection of subsets of ''T'' directed by inclusion. Suppose in addition that ''Y'' is a topological vector space (not necessarily Hausdorff or locally convex) and that is a basis of neighborhoods of 0 in ''Y''. Then the set of all functions from ''T'' into ''Y'', , can be given a unique translation-invariant topology by defining a basis of neighborhoods of 0 in , to be : as ''G'' and ''N'' range over all and . This topology does not depend on the basis that was chosen and it is known as the topology of uniform convergence on the sets in or as the -topology.〔Schaefer (1970) p. 79〕 In practice, usually consists of a collection of sets with certain properties and this name is changed appropriately to reflect this set so that if, for instance, is the collection of compact subsets of ''T'' (and ''T'' is a topological space), then this topology is called the topology of uniform convergence on the compact subsets of ''T''. A set of is said to be fundamental with respect to if each is a subset of some element in . In this case, the collection can be replaced by without changing the topology on .〔 However, the -topology on is not necessarily compatible with the vector space structure of or of any of its vector subspaces (that is, it is not necessarily a topological vector space topology on ). Suppose that ''F'' is a vector subspace so that it inherits the subspace topology from . Then the -topology on ''F'' is compatible with the vector space structure of ''F'' if and only if for every and every ''f'' ∈ ''F'', ''f''(''G'') is bounded in ''Y''.〔 If ''Y'' is locally convex then so is the -topology on and if is a family of continuous seminorms generating this topology on ''Y'' then the -topology is induced by the following family of seminorms: , as ''G'' varies over and varies over all indices.〔Schaefer (1970) p. 81〕 If ''Y'' is Hausdorff and ''T'' is a topological space such that -topology on subspace of consisting of all continuous maps is Hausdorff. If the topological space ''T'' is also a topological vector space, then the condition that -topology if and only if for every , is bounded in ''Y''.〔Schaefer (1970) p. 81〕 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Topology of uniform convergence」の詳細全文を読む スポンサード リンク
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