The point of departure for the present work is Barry Mitchell's 1972 theorem that the
cohomological dimension of ℵ n is n+ 1. We record a new proof and mild strengthening of …

In this paper, the first in a projected two-part series, we describe an organizing framework for
the study of infinitary combinatorics. This framework is\v {C} ech cohomology. We show in …

Considering topological properties of set theoretical constructions is an active area of
research in combinatorial set theory. Various tools allowing us to compute properties of …