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Related papers: Relative equivariant motives and modules

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In the present article we investigate ordinary and equivariant Rost motives. We provide an equivariant motivic decomposition of the variety X of full flags of a split semisimple algebraic group over a smooth base scheme, study torsion…

Algebraic Geometry · Mathematics 2017-06-14 Victor Petrov , Nikita Semenov

Let G be a split semisimple linear algebraic group over a field k0. Let E be a G-torsor over a field extension k of k0. Let h be an algebraic oriented cohomology theory in the sense of Levine-Morel. Consider a twisted form E/B of the…

Algebraic Geometry · Mathematics 2016-06-27 Alexander Neshitov , Victor Petrov , Nikita Semenov , Kirill Zainoulline

Let G be an adjoint simple algebraic group of inner type. We express the Chow motive (with integral coefficients) of some anisotropic projective G-homogeneous varieties in terms of motives of simpler G-homogeneous varieties, namely, those…

Algebraic Geometry · Mathematics 2008-03-07 B. Calmes , V. Petrov , N. Semenov , K. Zainoulline

Let $G$ be a semi-simple algebraic group over a perfect field $k$. A lot of progress has been made recently in computing the Chow motives of projective $G$-homogenous varieties. When $k$ has positive characteristic, a broader class of…

Algebraic Geometry · Mathematics 2017-10-20 Srimathy Srinivasan

For an oriented cohomology theory A and a relative cellular space X, we decompose the A-motive of X into a direct sum of twisted motives of the base spaces. We also obtain respective decompositions of the A-cohomology of X. Applying them,…

Algebraic Geometry · Mathematics 2007-05-23 A. Nenashev , K. Zainoulline

For a variety with a Whitney stratification by affine spaces, we study categories of motivic sheaves which are constant mixed Tate along the strata. We are particularly interested in those cases where the category of mixed Tate motives over…

Representation Theory · Mathematics 2016-03-02 Wolfgang Soergel , Matthias Wendt

We use the construction of the stable homotopy category by Khan-Ravi to calculate the integral $T$-equivariant $K$-theory spectrum of a flag variety over an affine scheme, where $T$ is a split torus associated to the flag variety. More…

Algebraic Geometry · Mathematics 2025-08-20 Can Yaylali

We study the Milnor-Witt motives which are a finite direct sum of $\mathbb{Z}(q)[p]$ and $\mathbb{Z}/\eta(q)[p]$. We show that for MW-motives of this type, we could determine an MW-motivic cohomology class in terms of a motivic cohomology…

Algebraic Geometry · Mathematics 2022-10-31 Nanjun Yang

Let X be a geometrically split, geometrically irreducible variety over a field F satisfying Rost nilpotence principle. Consider a field extension E/F and a finite field K. We provide in this note a motivic tool giving sufficient conditions…

Algebraic Geometry · Mathematics 2012-09-14 Charles De Clercq

We extend the notion of the $J$-invariant to arbitrary semisimple linear algebraic groups and provide complete decompositions for the normed Chow motives of all generically quasi-split twisted flag varieties. Besides, we establish some…

Algebraic Geometry · Mathematics 2025-10-29 Nikita Geldhauser , Maksim Zhykhovich

Making use of noncommutative motives we relate exceptional collections (and more generally semi-orthogonal decompositions) to motivic decompositions. On one hand we prove that the Chow motive M(X) of every smooth proper Deligne-Mumford…

Algebraic Geometry · Mathematics 2013-03-14 Matilde Marcolli , Goncalo Tabuada

This paper introduces a two-parameter deformation of the cohomology of generalized flag varieties. One special case is the Belkale-Kumar deformation (used to study eigencones of Lie groups). Another picks out intersections of Schubert…

Algebraic Geometry · Mathematics 2018-07-12 Oliver Pechenik , Dominic Searles

We associate weight complexes of (homological) motives, and hence Euler characteristics in the Grothendieck group of motives, to arithmetic varieties and Deligne-Mumford stacks; this extends the results in the paper "Descent, Motives and…

Algebraic Geometry · Mathematics 2009-05-28 Henri Gillet , Christophe Soulé

This an extended version of the previous preprint dated by February 2005. We prove that the Chow motive of an anisotropic projective homogeneous variety of type F4 is isomorphic to the direct sum of twisted copies of a generalized Rost…

Algebraic Geometry · Mathematics 2010-01-12 S. Nikolenko , N. Semenov , K. Zainoulline

We provide a proof that every Schubert variety of a semi-infinite flag variety is projectively normal. This gives us an interpretation of a Demazure module of a global Weyl module of a current Lie algebra as the (dual) space of the space of…

Representation Theory · Mathematics 2018-09-06 Syu Kato

The study of Chow varieties of decomposable forms lies at the confluence of algebraic geometry, commutative algebra, representation theory and combinatorics. There are many open questions about homological properties of Chow varieties and…

Commutative Algebra · Mathematics 2022-06-22 Claudiu Raicu , Steven V Sam , Jerzy Weyman

In this note we relate the notions of Lefschetz type, decomposability, and isomorphism, on Chow motives with the notions of unit type, decomposability, and isomorphism, on noncommutative motives. Examples, counter-examples, and applications…

Algebraic Geometry · Mathematics 2014-09-11 Marcello Bernardara , Goncalo Tabuada

We prove that the group of normalized cohomological invariants of degree 3 modulo the subgroup of semidecomposable invariants of a semisimple split linear algebraic group G is isomorphic to the torsion part of the Chow group of codimension…

Algebraic Geometry · Mathematics 2015-08-19 Alexander Merkurjev , Alexander Neshitov , Kirill Zainoulline

We prove a short, root-system uniform, combinatorial classification of Levi-spherical Schubert varieties for any generalized flag variety $G/B$ of finite Lie type. We apply this to the study of multiplicity-free decompositions of a Demazure…

Representation Theory · Mathematics 2024-03-25 Yibo Gao , Reuven Hodges , Alexander Yong

Building on the theory of parity sheaves due to Juteau-Mautner-Williamson, we develop a formalism of "mixed modular perverse sheaves" for varieties equipped with a stratification by affine spaces. We then give two applications: (1) a…

Representation Theory · Mathematics 2016-02-10 Pramod N. Achar , Simon Riche
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