Existence of a topology on arbitrary universal completions

Determine whether the universal completion of an arbitrary Archimedean vector lattice can be equipped with a topology possessing properties analogous to the gauge-metric topology constructed under the paper’s additional assumptions.

Background

The paper constructs a gauge metric on the universal completion Eu of a Dedekind σ-complete Banach lattice E with order-continuous norm and a weak unit e, using a strictly positive order-continuous functional. The resulting metric generates a locally solid topology with the σ-Lebesgue property and is essential for applying the abstract Banach principle to prove the individual ergodic theorem.

The authors explicitly leave unresolved whether an arbitrary universal completion admits any topology of this kind in the absence of the stated structural assumptions. This is a foundational question for extending the paper’s representation-free framework beyond the class of lattices for which the gauge construction is available.

References

It is unclear to the author if the universal completion can be equipped with a topology in general.

Banach's principle in vector lattices  (2608.14272 - Dobrick, 14 Aug 2026) in Page 11, Section 3, subsection “The gauge metric”