Simutaneously vanishing higher derived limits without large cardinals
Abstract
A question dating to Sibe Marde\v{s}i\'{c} and Andrei Prasolov's 1988 work Strong homology is not additive, and motivating a considerable amount of set theoretic work in the ensuing years, is that of whether it is consistent with the ZFC axioms for the higher derived limits of a certain inverse system indexed by to simultaneously vanish. An equivalent formulation of this question is that of whether it is consistent for all -coherent families of functions indexed by to be trivial. In this paper, we prove that, in any forcing extension given by adjoining -many Cohen reals, vanishes for all . Our proof involves a detailed combinatorial analysis of the forcing extension and repeated applications of higher dimensional -system lemmas. This work removes all large cardinal hypotheses from the main result of arXiv:1907.11744 and substantially reduces the least value of the continuum known to be compatible with the simultaneous vanishing of for all .
Keywords
Cite
@article{arxiv.2102.06699,
title = {Simutaneously vanishing higher derived limits without large cardinals},
author = {Jeffrey Bergfalk and Michael Hrušák and Chris Lambie-Hanson},
journal= {arXiv preprint arXiv:2102.06699},
year = {2021}
}
Comments
30 pages, 1 figure