Newtonian spaces based on quasi-Banach function lattices
(English)In: Mathematica Scandinavica, ISSN 0025-5521Article in journal (Refereed) Accepted
In this paper, first-order Sobolev-type spaces on abstract metric measure spaces are defined using the notion of (weak) upper gradients, where the summability of a function and its upper gradient is measured by the “norm” of a quasi-Banach function lattice. This approach gives rise to so-called Newtonian spaces. Tools such as moduli of curve families and Sobolev capacity are developed, which allows us to study basic properties of these spaces. The absolute continuity of Newtonian functions along curves and the completeness of Newtonian spaces in this general setting are established.
Newtonian space, upper gradient, weak upper gradient, Sobolev-type space, Banach function lattice, quasi-normed space, metric measure space
IdentifiersURN: urn:nbn:se:liu:diva-79164OAI: oai:DiVA.org:liu-79164DiVA: diva2:538660