Zobrazeno 1 - 10
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pro vyhledávání: '"Postnikov, Alexander"'
We relate the Fourier transform of perverse sheaves smooth along the coordinate hyperplane configuration in a complex vector space to the Deligne-Lusztig duality of unipotent representations of a general linear group over a finite field. A similar re
Externí odkaz:
http://arxiv.org/abs/2206.00324
Publikováno v:
Combinatorial Theory, Volume 4, Number 2 (2024)
We study the maximum multiplicity $\mathcal{M}(k,n)$ of a simple transposition $s_k=(k \: k+1)$ in a reduced word for the longest permutation $w_0=n \: n-1 \: \cdots \: 2 \: 1$, a problem closely related to much previous work on sorting networks and
Externí odkaz:
http://arxiv.org/abs/2204.03033
Autor:
Dya, German A., Lebedeva, Olga S., Gushchevarov, Daniil A., Volovikov, Egor A., Belikova, Lilia D., Kopylova, Irina V., Postnikov, Alexander B., Artemieva, Marina M., Medvedeva, Natalia A., Lagarkova, Maria A., Katrukha, Alexey G., Serebryanaya, Daria V.
Publikováno v:
In Biochemical and Biophysical Research Communications 12 November 2024 733
Autor:
Erofeeva, Kseniya G., Samsonov, Alexander V., Larionov, Alexander N., Pilitsyna, Tatiana A., Postnikov, Alexander V., Sabirov, Ilnur A., Vovshina, Anna Yu., Borisovsky, Sergey E., Golovanova, Tatiana I., Dubenskiy, Alexander S., Sheshukov, Viktor S.
Publikováno v:
In Gondwana Research May 2024 129:53-74
Publikováno v:
In Journal of Combinatorial Theory, Series A January 2024 201
Autor:
Lam, Thomas, Postnikov, Alexander
We initiate the study of a class of polytopes, which we coin polypositroids, defined to be those polytopes that are simultaneously generalized permutohedra (or polymatroids) and alcoved polytopes. Whereas positroids are the matroids arising from the
Externí odkaz:
http://arxiv.org/abs/2010.07120
Given a configuration $A$ of $n$ points in $\mathbb{R}^{d-1}$, we introduce the higher secondary polytopes $\Sigma_{A,1},\dots, \Sigma_{A,n-d}$, which have the property that $\Sigma_{A,1}$ agrees with the secondary polytope of Gelfand--Kapranov--Zele
Externí odkaz:
http://arxiv.org/abs/1909.05435
We describe the cone of deformations of a Coxeter permutahedron, or equivalently, the nef cone of the toric variety associated to a Coxeter complex. This family of polytopes contains polyhedral models for the Coxeter-theoretic analogs of compositions
Externí odkaz:
http://arxiv.org/abs/1904.11029
Autor:
Postnikov, Alexander
The nonnegative Grassmannian is a cell complex with rich geometric, algebraic, and combinatorial structures. Its study involves interesting combinatorial objects, such as positroids and plabic graphs. Remarkably, the same combinatorial structures app
Externí odkaz:
http://arxiv.org/abs/1806.05307
Autor:
Hopkins, Sam, Postnikov, Alexander
Publikováno v:
Algebraic Combinatorics, 2(6), 2019
In earlier work in collaboration with Pavel Galashin and Thomas McConville we introduced a version of chip-firing for root systems. Our investigation of root system chip-firing led us to define certain polynomials analogous to Ehrhart polynomials of
Externí odkaz:
http://arxiv.org/abs/1803.08472