Abstract
We calculate the integer cohomology ring and stable tangent bundle of a family of compact, 3-Sasakian 7-manifolds constructed by Boyer, Galicki, Mann and Rees. The most important part of the cohomology ring is a previously undetermined torsion group that we describe explicitly and whose order we compute. There is a surprising connection with the combinatorics of trees.
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Hepworth, R.A. The topology of certain 3-Sasakian 7-manifolds. Math. Ann. 339, 733–755 (2007). https://doi.org/10.1007/s00208-007-0100-8
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DOI: https://doi.org/10.1007/s00208-007-0100-8