?
On Involutions in the Weyl Group and B-Orbit Closures in the Orthogonal Case
P. 331–355.
In book
Vol. 330. , Switzerland: Birkhauser/Springer, 2019.
Mikhail Ignatev, Mikhail Venchakov, Expositiones Mathematicae 2025 Vol. 43 No. 3 Article 125656
Let U be the unitriangular group over a finite field. We consider an interesting class of irreducible complex characters of U, so-called characters of depth 2. This is a next natural step after characters of maximal and submaximal dimension, whose description is already known. We explicitly describe the support of a character of depth 2 by a system ...
Added: February 14, 2025
Shirokov D., International Journal of Geometric Methods in Modern Physics 2026 Vol. 23 No. 5 Article 2540031
In this paper, we present a method for calculation of spin groups elements for known pseudo-orthogonal group elements with respect to the corresponding two-sheeted coverings. We present our results using the Clifford algebra formalism in the case of arbitrary dimension and signature, and then explicitly using matrices, quaternions, and split-quaternions in the cases of all ...
Added: December 5, 2024
Shirokov D., Advances in Applied Clifford Algebras 2024 Vol. 34 Article 23
In this paper, we present a natural implementation of singular value decomposition (SVD) and polar decomposition of an arbitrary multivector in nondegenerate real and complexified Clifford geometric algebras of arbitrary dimension and signature. The new theorems involve only operations in geometric algebras and do not involve matrix operations. We naturally define these and other related ...
Added: August 23, 2024
Ignatyev Mikhail V., Shevchenko A., Bochkarev M., Journal of Algebra 2016 Vol. 465 P. 259–286
We study tangent cones to Schubert subvarieties of the flag variety of a complex reductive group G. Let T be a maximal torus of G, B be a Borel subgroup of G containing T, Φ be the root system of G with respect to T, W be the Weyl group of Φ, and F = G/B be the flag variety. We prove that if every irreducible component of Φ is of type Bn or ...
Added: October 11, 2023
Shirokov D., Advances in Applied Clifford Algebras 2019 Vol. 29 No. 50 P. 1–12
We present a method of computing elements of spin groups in the case of arbitrary dimension. This method generalizes Hestenes method for the case of dimension 4. We use the method of averaging in Clifford’s geometric algebra previously proposed by the author. We present explicit formulas for elements of spin group that correspond to the ...
Added: July 22, 2019
Smirnov E., / Series arXiv "math". 2007.
The classical Ehresmann-Bruhat order describes the possible degenerations of a pair of flags in a finite-dimensional vector space V; or, equivalently, the closure of an orbit of the group GL(V) acting on the direct product of two full flag varieties.
We obtain a similar result for triples consisting of two subspaces and a partial flag in ...
Added: December 3, 2018
Bochkarev M., Ignatyev M. V., Shevchenko A. A., Journal of Algebra 2016 Vol. 465 No. November P. 259–286
We study tangent cones to Schubert subvarieties of the flag variety of a complex reductive group G. Let T be a maximal torus of G, B be a Borel subgroup of G containing T, Φ be the root system of G with respect to T, W be the Weyl group of Φ, and F=G/B be ...
Added: October 8, 2016
Shirokov D., P-Adic Numbers, Ultrametric Analysis, and Applications 2011 Vol. 3 No. 3 P. 212–218
In this article we consider Clifford algebras over the field of real numbers of finite dimension. We define the operation of Hermitian conjugation for the elements of Clifford algebra. This operation allows us to define the structure of Euclidian space on the Clifford algebra. We consider pseudo-orthogonal group and its subgroups – special pseudo-orthogonal, orthochronous, ...
Added: June 16, 2015
Shirokov D., Advances in Applied Clifford Algebras 2015 Vol. 25 No. 3 P. 707–718
In this paper we prove isomorphisms between 5 Lie groups (of arbitrary dimension and fixed signatures) in Clifford algebra and classical matrix Lie groups - symplectic, orthogonal and linear groups. Also we obtain isomorphisms of corresponding Lie algebras. ...
Added: March 12, 2015
Shirokov D., Advances in Applied Clifford Algebras 2015 Vol. 25 No. 1 P. 227–244
We formulate generalizations of Pauli’s theorem on the cases of real and complex Clifford algebras of even and odd dimensions. We give analogues of these theorems in matrix formalism. Using these theorems we present an algorithm for computing elements of spin groups that correspond to elements of orthogonal groups as double cover. ...
Added: March 11, 2015