Abstract:
It is known that for the natural algebraic torus actions on the Grassmannians, the closures of torus orbits are normal and hence are toric varieties, and that these toric varieties are smooth if and only if the corresponding matroid polytopes are simple. We prove that simple matroid polytopes are products of simplices and that smooth torus orbit closures in the Grassmannians are products of complex projective spaces. Moreover, it turns out that the smooth torus orbit closures are uniquely determined by the corresponding simple matroid polytopes.
The authors were partially supported by the bilateral program “Topology and Geometry of Torus Actions, Cohomological Rigidity, and Hyperbolic Manifolds” between JSPS and RFBR.
Citation:
Masashi Noji, Kazuaki Ogiwara, “The Smooth Torus Orbit Closures in the Grassmannians”, Algebraic topology, combinatorics, and mathematical physics, Collected papers. Dedicated to Victor Matveevich Buchstaber, Corresponding Member of the Russian Academy of Sciences, on the occasion of his 75th birthday, Trudy Mat. Inst. Steklova, 305, Steklov Math. Inst. RAS, Moscow, 2019, 271–282; Proc. Steklov Inst. Math., 305 (2019), 251–261
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\paper The Smooth Torus Orbit Closures in the Grassmannians
\inbook Algebraic topology, combinatorics, and mathematical physics
\bookinfo Collected papers. Dedicated to Victor Matveevich Buchstaber, Corresponding Member of the Russian Academy of Sciences, on the occasion of his 75th birthday
\serial Trudy Mat. Inst. Steklova
\yr 2019
\vol 305
\pages 271--282
\publ Steklov Math. Inst. RAS
\publaddr Moscow
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\jour Proc. Steklov Inst. Math.
\yr 2019
\vol 305
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Linking options:
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https://doi.org/10.4213/tm4013
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This publication is cited in the following 2 articles:
Victor M. Buchstaber, Svjetlana Terzić, Fields Institute Communications, 89, Toric Topology and Polyhedral Products, 2024, 81
V. M. Buchstaber, S. Terzić, “Resolution of Singularities of the Orbit Spaces $G_{n,2}/T^n$”, Proc. Steklov Inst. Math., 317 (2022), 21–54