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pro vyhledávání: '"Wiemeler, Michael"'
Autor:
Wiemeler, Michael
We prove vanishing results for Witten genera of string generalized complete intersections in homogeneous $\text{Spin}^c$-manifolds and in other $\text{Spin}^c$-manifolds with Lie group actions. By applying these results to Fano manifolds with second
Externí odkaz:
http://arxiv.org/abs/2410.21412
Autor:
Krishnan, Anusha M., Wiemeler, Michael
We show that ten-dimensional closed simply connected positively curved manifolds with isometric effective actions of three-dimensional tori are homotopy spheres or homotopy complex projective spaces.
Comment: 16 pages
Comment: 16 pages
Externí odkaz:
http://arxiv.org/abs/2310.12689
Autor:
Wiemeler, Michael
Publikováno v:
Proc. Amer. Math. Soc. 152 (2024), no. 8, 3617-3621
In 1996 Stolz conjectured that a string manifold with positive Ricci curvature has vanishing Witten genus. Here we prove this conjecture for toric string Fano manifolds and for string torus manifolds admitting invariant metrics of non-negative sectio
Externí odkaz:
http://arxiv.org/abs/2310.08456
Autor:
Wiemeler, Michael
We study smooth, closed orientable $S^1$-manifolds $M$ with exactly $3$ fixed points. We show that the dimension of $M$ is of the form $4\cdot 2^a$ or $8\cdot(2^a+2^b)$ with $a,b\geq 0$ and $a\neq b$. Moreover, under the extra assumption that $M$ is
Externí odkaz:
http://arxiv.org/abs/2303.15396
We identify a link between regular matroids and torus representations all of whose isotropy groups have an odd number of components. Applying Seymour's 1980 classification of the former objects, we obtain a classification of the latter. In addition,
Externí odkaz:
http://arxiv.org/abs/2212.08152
Autor:
Wiemeler, Michael
We discuss the rigidity of elliptic genera for non-spin manifolds $M$ with $S^1$-action. We show that if the universal covering of $M$ is spin, then the universal elliptic genus of $M$ is rigid. Moreover, we show that there is no condition which only
Externí odkaz:
http://arxiv.org/abs/2212.01059
A 1930s conjecture of Hopf states that an even-dimensional compact Riemannian manifold with positive sectional curvature has positive Euler characteristic. We prove this conjecture under the additional assumption that the isometry group has rank at l
Externí odkaz:
http://arxiv.org/abs/2106.14723
Autor:
Ebert, Johannes, Wiemeler, Michael
Publikováno v:
J. Eur. Math. Soc. (JEMS) 26 (2024), no. 9, 3327-3363
Let $M^d$ be a simply connected spin manifold of dimension $d \geq 5$ admitting Riemannian metrics of positive scalar curvature. Denote by $\mathcal{R}^+(M^d)$ the space of such metrics on $M^d$. We show that $\mathcal{R}^+(M^d)$ is homotopy equivale
Externí odkaz:
http://arxiv.org/abs/2012.00432
Autor:
Wiemeler, Michael
Publikováno v:
Osaka J. Math. 59 (2022) No. 3, 549-557
We study locally standard $T^k$-manifolds $M$. In particular, we study the case where there is a continuous section to the orbit map $\pi : M \rightarrow M/T$. We give a classification of $T^k$-manifolds satisfying these conditions up to equivariant
Externí odkaz:
http://arxiv.org/abs/2011.10460
Autor:
Wiemeler, Michael
Publikováno v:
Arch. Math. 114 (2020), 641-647
In this note we classify simply connected rationally elliptic compact toric orbifolds up to algebraic isomorphism.
Comment: 6 pages; to appear in Arch. Math
Comment: 6 pages; to appear in Arch. Math
Externí odkaz:
http://arxiv.org/abs/1906.01335