Non-vanishing higher derived limits
Abstract: In the study of strong homology Marde\v{s}i\'c and Prasolov isolated a certain inverse system of abelian groups indexed by elements of . They showed that if strong homology is additive on a class of spaces containing closed subsets of Euclidean spaces then the higher derived limits must vanish, for $n>0$. They also proved that under the Continuum Hypothesis . The question whether vanishes, for $n>0$, has attracted considerable interest from set theorists. Dow, Simon and Vaughan showed that under PFA . Bergfalk show that it is consistent that does not vanish. Later Bergfalk and Lambie-Hanson showed that, modulo a weakly compact cardinal, it is relatively consistent with ZFC that , for all . The large cardinal assumption was recently removed by Bergfalk, Hru\v{s}ak and Lambie-Henson. We complete the picture by showing that, for any $n>0$, it is relatively consistent with ZFC that .
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