Projective tensor product

In functional analysis, an area of mathematics, the projective tensor product of two locally convex topological vector spaces is a natural topological vector space structure on their tensor product.

Namely, given locally convex topological vector spaces

a locally convex topological vector space such that the canonical map

and called the projective tensor product of

be locally convex topological vector spaces.

is the unique locally convex topological vector space with underlying vector space

is the balanced convex hull of the set

is generated by the collection of such tensor products of the seminorms on

[3] Throughout, all spaces are assumed to be locally convex.

denotes the completion of the projective tensor product of

can always be linearly embedded as a dense vector subspace of some complete locally convex TVS, which is generally denoted by

, namely, the space of continuous bilinear forms

[9] In a Hausdorff locally convex space

[10] The following fundamental result in the theory of topological tensor products is due to Alexander Grothendieck.

be metrizable locally convex TVSs and let

is the sum of an absolutely convergent series

The next theorem shows that it is possible to make the representation of

) be a balanced open neighborhood of the origin in

be a compact subset of the convex balanced hull of

denote the families of all bounded subsets of

is the space of continuous bilinear forms

the topology of uniform convergence on sets in

which is also called the topology of bi-bounded convergence.

This is equivalent to the problem: Given a bounded subset

is a subset of the closed convex hull of

Grothendieck proved that these topologies are equal when

They are also equal when both spaces are Fréchet with one of them being nuclear.

be a locally convex topological vector space and let

be locally convex topological vector spaces with

Then, denoting strong dual spaces with a subscripted