Cohomology ring of tree braid groups and exterior face rings
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- by Jesús González and Teresa Hoekstra-Mendoza HTML | PDF
- Trans. Amer. Math. Soc. Ser. B 9 (2022), 1065-1101
Abstract:
For a tree $T$ and a positive integer $n$, let $B_nT$ denote the $n$-strand braid group on $T$. We use discrete Morse theory techniques to show that the cohomology ring $H^*(B_nT)$ is encoded by an explicit abstract simplicial complex $K_nT$ that measures $n$-local interactions among essential vertices of $T$. We show that, in many cases (for instance when $T$ is a binary tree), $H^*(B_nT)$ is the exterior face ring determined by $K_nT$.References
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Additional Information
- Jesús González
- Affiliation: Departamento de Matemáticas, Centro de Investigación y de Estudios Avanzados del I.P.N., Av. Instituto Politécnico Nacional número 2508, San Pedro Zacatenco, México City 07000, México
- ORCID: 0000-0003-3541-3369
- Email: jesus@math.cinvestav.mx
- Teresa Hoekstra-Mendoza
- Affiliation: Departamento de Matemáticas, Centro de Investigación y de Estudios Avanzados del I.P.N., Av. Instituto Politécnico Nacional número 2508, San Pedro Zacatenco, México City 07000, México
- MR Author ID: 1300977
- Email: idskjen@math.cinvestav.mx
- Received by editor(s): January 12, 2022
- Received by editor(s) in revised form: June 10, 2022
- Published electronically: December 21, 2022
- © Copyright 2022 by the authors under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License (CC BY NC ND 4.0)
- Journal: Trans. Amer. Math. Soc. Ser. B 9 (2022), 1065-1101
- MSC (2020): Primary 20F36, 55R80, 57M15, 57Q70
- DOI: https://doi.org/10.1090/btran/131
- MathSciNet review: 4524602