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Schubert Calculus on Newton–Okounkov Polytopes
P. 233–249.
Kiritchenko V., Padalko M.
A Newton–Okounkov polytope of a complete flag variety can be turned into a convex geometric model for Schubert calculus. Namely, we can represent Schubert cycles by linear combinations of faces of the polytope so that the intersection product of cycles corresponds to the set-theoretic intersection of faces (whenever the latter are transverse). We explain the general framework and survey particular realizations of this approach in types A, B and C.
Kiritchenko V., Journal of Combinatorial Theory, Series A 2025 Vol. 213 Article 106022
We construct simple geometric operations on faces of the Cayley sum of two polytopes. These operations can be thought of as convex geometric counterparts of divided difference operators in Schubert calculus. We show that these operations give a uniform construction of Knutson–Miller mitosis in the type A and Fujita mitosis in the type C on Kogan faces of Gelfand–Zetlin ...
Added: March 18, 2025
Deviatov R., / Series arXiv "math". 2025.
We sketch the proof of a connection between the canonical (0-)dimension of semisimple split simply connected groups and cohomology of their full flag varieties. Using this connection, we get a new estimate of the canonical (0-)dimension of simply connected split exceptional groups of type E understood as a group. ...
Added: March 12, 2025
Presnova E., Smirnov E., / Series math "arxiv.org". 2023. No. 2312.01417.
We give a new combinatorial description for stable Grothendieck polynomials in terms of subdivisions of Gelfand-Zetlin polytopes. Moreover, these subdivisions also provide a description of Lascoux polynomials. This generalizes a similar result on key polynomials by Kiritchenko, Smirnov, and Timorin. ...
Added: February 12, 2024
Kiritchenko V., / Series arXiv "math". 2023.
We construct simple geometric operations on faces of the Cayley sum of two polytopes. These operations can be thought of as convex geometric counterparts of divided difference operators in Schubert calculus. We show that these operations give a uniform construction of Knutson-Miller mitosis (in type A) and (simplified) Fujita mitosis (in type C) on Kogan ...
Added: December 3, 2023
Evgeny Smirnov, Anna Tutubalina, European Journal of Combinatorics 2023 Vol. 107 Article 103613
Schubert polynomials for the classical groups were defined by S.Billey and M.Haiman in 1995; they are polynomial representatives of Schubert classes in a full flag variety over a classical group. We provide a combinatorial description for these polynomials, as well as their double versions, by introducing analogues of pipe dreams, or RC-graphs, for Weyl groups ...
Added: September 14, 2022
Mathematical Society of Japan, 2016.
This volume contains the proceedings of the 5th MSJ Seasonal Institute on Schubert Calculus, held at Osaka City University, from September 17–27, 2012. It is recommended for all researchers and graduate students who are interested in Schubert calculus and its many connections and applications to related areas of mathematics, such as geometric representation theory, combinatorial ...
Added: October 19, 2020
Kiritchenko V., Padalko M., / Series arXiv "math". 2018.
A Newton-Okounkov polytope of a complete flag variety can be turned into a convex geometric model for Schubert calculus. Namely, we can represent Schubert cycles by linear combinations of faces of the polytope so that the intersection product of cycles corresponds to the set-theoretic intersection of faces (whenever the latter are transverse). We explain the ...
Added: October 15, 2019
Smirnov E., В кн.: Тезисы докладов седьмой школы-конференции "Алгебры Ли, алгебраические группы и теория инвариантов".: Самара: Инсома-пресс, 2018. С. 43–44.
We define simplicial complexes for slide polynomials and show that they are always homeomorphic to balls or spheres. ...
Added: October 7, 2019
Makhlin I., Функциональный анализ и его приложения 2016 Т. 50 № 2 С. 20–30
Работа посвящена следующему наблюдению: характер неприводимого gl_n-модуля (многочлен Шура) может быть вычислен при помощи теоремы Бриона, будучи равным сумме экспонент целых точек многогранника Гельфанда–Цетлина. Основной результат заключается в том, что в случае регулярного старшего веса вклады всех несимплициальных вершин оказываются равными нулю, а число симплициальных есть n! и их вклады суть в точности слагаемые в формуле ...
Added: September 5, 2016
Valentina Kiritchenko, Mathematical Research Letters 2016 Vol. 23 No. 4 P. 1069–1096
We describe an elementary convex geometric algorithm for realizing Schubert cycles in complete flag varieties by unions of faces of polytopes. For GL_n and Gelfand{Zetlin polytopes, combinatorics of this algorithm coincides with that of the mitosis on pipe dreams introduced by Knutson and Miller. For Sp_4 and a Newton{Okounkov polytope of the symplectic flag variety, ...
Added: February 25, 2016
Kiritchenko V., / Series math "arxiv.org". 2014.
We describe an elementary convex geometric algorithm for realizing Schubert cycles in complete flag varieties by unions of faces of polytopes. For GL_n and Gelfand--Zetlin polytopes, combinatorics of this algorithm coincides with that of the mitosis on pipe dreams introduced by Knutson and Miller. For Sp_4 and a Newton--Okounkov polytope of the symplectic flag variety, ...
Added: September 17, 2014