topological vector lattice

{{one source|date=June 2020}}

In mathematics, specifically in functional analysis and order theory, a topological vector lattice is a Hausdorff topological vector space (TVS) X that has a partial order \,\leq\, making it into vector lattice that possesses a neighborhood base at the origin consisting of solid sets.{{sfn|Schaefer|Wolff|1999|pp=234–242}}

Ordered vector lattices have important applications in spectral theory.

Definition

If X is a vector lattice then by the vector lattice operations we mean the following maps:

  1. the three maps X to itself defined by x \mapsto|x |, x \mapsto x^+, x \mapsto x^{-}, and
  2. the two maps from X \times X into X defined by (x, y) \mapsto \sup_{} \{ x, y \} and(x, y) \mapsto \inf_{} \{ x, y \}.

If X is a TVS over the reals and a vector lattice, then X is locally solid if and only if (1) its positive cone is a normal cone, and (2) the vector lattice operations are continuous.{{sfn|Schaefer|Wolff|1999|pp=234–242}}

If X is a vector lattice and an ordered topological vector space that is a Fréchet space in which the positive cone is a normal cone, then the lattice operations are continuous.{{sfn|Schaefer|Wolff|1999|pp=234–242}}

If X is a topological vector space (TVS) and an ordered vector space then X is called locally solid if X possesses a neighborhood base at the origin consisting of solid sets.{{sfn|Schaefer|Wolff|1999|pp=234–242}}

A topological vector lattice is a Hausdorff TVS X that has a partial order \,\leq\, making it into vector lattice that is locally solid.{{sfn|Schaefer|Wolff|1999|pp=234–242}}

Properties

Every topological vector lattice has a closed positive cone and is thus an ordered topological vector space.{{sfn|Schaefer|Wolff|1999|pp=234–242}}

Let \mathcal{B} denote the set of all bounded subsets of a topological vector lattice with positive cone C and for any subset S, let [S]_C := (S + C) \cap (S - C) be the C-saturated hull of S.

Then the topological vector lattice's positive cone C is a strict \mathcal{B}-cone,{{sfn|Schaefer|Wolff|1999|pp=234–242}} where C is a strict \mathcal{B}-cone means that \left\{ [B]_C : B \in \mathcal{B} \right\} is a fundamental subfamily of \mathcal{B} that is, every B \in \mathcal{B} is contained as a subset of some element of \left\{ [B]_C : B \in \mathcal{B} \right\}).{{sfn|Schaefer|Wolff|1999|pp=215–222}}

If a topological vector lattice X is order complete then every band is closed in X.{{sfn|Schaefer|Wolff|1999|pp=234–242}}

Examples

The Lp spaces (1 \leq p \leq \infty) are Banach lattices under their canonical orderings.

These spaces are order complete for p < \infty.

See also

  • {{annotated link|Banach lattice}}
  • {{annotated link|Complemented lattice}}
  • {{annotated link|Fréchet lattice}}
  • {{annotated link|Locally convex vector lattice}}
  • {{annotated link|Normed lattice}}
  • {{annotated link|Ordered vector space}}
  • {{annotated link|Pseudocomplement}}
  • {{annotated link|Riesz space}}

References

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Bibliography

  • {{Narici Beckenstein Topological Vector Spaces|edition=2}}
  • {{Schaefer Wolff Topological Vector Spaces|edition=2}}

{{Functional analysis}}

{{Ordered topological vector spaces}}

{{Order theory}}

Category:Functional analysis