PreprintCC BY-NC-ND 4.0arXiv
Homotopical Nilpotency and Homology Nilpotency: A Dimension--Connectivity Bound
Abstract
Let X be a (q−1)-connected rational space of finite type, where q≥2, with homotopical nilpotency nilh(X)=n≥1. If H>N(X;Q)=0 and N≤ q(n+3)−3, we prove that Hnil(X)=n. More precisely, the sufficient bound is N≤ an(MX)+2q−3, where an(MX) is the first nonzero internal cohomology degree of (MX+)n+1 in the minimal model. A family of examples proves that the constant −3 in this refined bound is optimal; optimality of the uniform bound is not asserted. The proof uses two stages of adjoining primitives to an ideal of the fixed minimal model.
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BibTeX
@misc{parent2026homotopical,
title = {{Homotopical Nilpotency and Homology Nilpotency: A Dimension--Connectivity Bound}},
author = {Paul-Eugene Parent},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.06518},
eprint = {2609.06518},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.06518},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Homotopical Nilpotency and Homology Nilpotency: A Dimension--Connectivity Bound
AU - Paul-Eugene Parent
PY - 2026
DA - 2026/09/06
PB - arXiv
DO - 10.48550/arxiv.2609.06518
UR - https://arxiv.org/abs/2609.06518
AB - Let X be a (q−1)-connected rational space of finite type, where q≥2, with homotopical nilpotency nil_h(X)=n≥1. If H^>N(X;Q)=0 and N≤ q(n+3)−3, we prove that Hnil(X)=n. More precisely, the sufficient bound is N≤ a_n(M_X)+2q−3, where a_n(M_X) is the first nonzero internal cohomology degree of (M_X^+)^n+1 in the minimal model. A family of examples proves that the constant −3 in this refined bound is optimal; optimality of the uniform bound is not asserted. The proof uses two stages of adjoining primitives to an ideal of the fixed minimal model.
ER -