Bornivorous set

In functional analysis, a subset of a real or complex vector space

is a topological vector space (TVS) then a subset

Bornivorous sets play an important role in the definitions of many classes of topological vector spaces, particularly bornological spaces.

absorbs every bounded subset of

An absorbing disk in a locally convex space is bornivorous if and only if its Minkowski functional is locally bounded (i.e. maps bounded sets to bounded sets).

[1] A linear map between two TVSs is called infrabounded if it maps Banach disks to bounded disks.

is called infrabornivorous if it absorbs every Banach disk.

[3] An absorbing disk in a locally convex space is infrabornivorous if and only if its Minkowski functional is infrabounded.

[1] A disk in a Hausdorff locally convex space is infrabornivorous if and only if it absorbs all compact disks (that is, if it is "compactivorous").

[1] Every bornivorous and infrabornivorous subset of a TVS is absorbing.

In a pseudometrizable TVS, every bornivore is a neighborhood of the origin.

[4] Two TVS topologies on the same vector space have that same bounded subsets if and only if they have the same bornivores.

is a vector subspace of finite codimension in a locally convex space

then there exists a barrel (resp.

[6] Every neighborhood of the origin in a TVS is bornivorous.

is a TVS in which every bounded subset is contained in a finite dimensional vector subspace, then every absorbing set is a bornivore.

is the balanced hull of the closed line segment between

is not bornivorous but the convex hull of

is the closed and "filled" triangle with vertices