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 $\mathrm{ lim}^n$ $(n>0)$ of a certain inverse system $\mathbf{ A}$ indexed by ${ ^\omega}\omega$ to simultaneously vanish. An equivalent formulation of this question is that of whether it is consistent for all $n$-coherent families of functions indexed by ${ ^\omega}\omega$ to be trivial. In this paper, we prove that, in any forcing extension given by adjoining $\beth_\omega$-many Cohen reals, $\mathrm{ lim}^n \mathbf{ A}$ vanishes for all $n > 0$. Our proof involves a detailed combinatorial analysis of the forcing extension and repeated applications of higher dimensional $\Delta$-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 $\mathrm{ lim}^n \mathbf{ A}$ for all $n > 0$.

Categories: math.LO math.AT

Simutaneously vanishing higher derived limits without large cardinals