PreprintCC BY 4.0arXiv
Prüfer $2$-group and Milnor's Conjecture on Fundamental Groups
Abstract
We construct complete, one-ended Riemannian manifolds in dimensions four and five having strictly positive Ricci curvature, with fundamental group isomorphic to the Prüfer $2$-group C2∞ and any subgroup Γ≤ ℚ/ℤ, respectively. This gives counterexamples to Milnor's conjecture in the two remaining dimensions.
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BibTeX
@misc{wu2026prüfer,
title = {{Prüfer $2$-group and Milnor's Conjecture on Fundamental Groups}},
author = {Nan Wu and Zetian Yan},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2608.15505},
eprint = {2608.15505},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.15505},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Prüfer $2$-group and Milnor's Conjecture on Fundamental Groups
AU - Nan Wu
AU - Zetian Yan
PY - 2026
DA - 2026/10/12
PB - arXiv
DO - 10.48550/arxiv.2608.15505
UR - https://arxiv.org/abs/2608.15505
AB - We construct complete, one-ended Riemannian manifolds in dimensions four and five having strictly positive Ricci curvature, with fundamental group isomorphic to the Prüfer $2$-group C_2^∞ and any subgroup Γ≤ ℚ/ℤ, respectively. This gives counterexamples to Milnor's conjecture in the two remaining dimensions.
ER -