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Related papers: Generic algebras with involution of degree 8m

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Let $1\leq m \leq n$ be integers with $m|n$ and $\cat{Alg}_{n,m}$ the class of central simple algebras of degree $n$ and exponent dividing $m$. In this paper, we find new, improved upper bounds for the essential dimension and 2-dimension of…

Rings and Algebras · Mathematics 2014-02-26 Sanghoon Baek

To an orthogonal or unitary involution on a central simple algebra of degree 4, or to a symplectic involution on a central simple algebra of degree 8, we associate a Pfister form that characterises the decomposability of the algebra with…

Rings and Algebras · Mathematics 2024-09-17 Karim Johannes Becher , Nicolas Grenier-Boley , Jean-Pierre Tignol

The projective orthogonal and symplectic groups $PO_n(F)$ and $PSp_n(F)$ have a natural action on the $F$ vector space $V' = M_n(F) \oplus ... \oplus M_n(F)$. Here we assume $F$ is an infinite field of characteristic not 2. If we assume…

Algebraic Geometry · Mathematics 2016-09-07 David J. Saltman

Let $k$ be an algebraically closed base field of characteristic zero. The category equivalence between central simple algebras and irreducible, generically free $PGL_n$-varieties is extended to the context of central simple algebras with…

Rings and Algebras · Mathematics 2009-07-10 Nikolaus Vonessen

Let $F$ be a field of characteristic zero. We prove that if a group grading on $UT_m(F)$ admits a graded involution then this grading is a coarsening of a $\mathbb{Z}^{\lfloor\frac{m}{2}\rfloor}$-grading on $UT_m(F)$ and the graded…

Rings and Algebras · Mathematics 2023-05-16 Diogo Diniz , Alex Ramos

Given a central simple algebra with involution over an arbitrary field, \'etale subalgebras contained in the space of symmetric elements are investigated. The method emphasizes the similarities between the various types of involutions and…

K-Theory and Homology · Mathematics 2017-10-20 Karim Johannes Becher , Nicolas Grenier-Boley , Jean-Pierre Tignol

We study central simple algebras with involution of the first kind that become hyperbolic over the function field of the conic associated to a given quaternion algebra $Q$. We classify these algebras in degree~4 and give an example of such…

Rings and Algebras · Mathematics 2008-12-18 Anne Quéguiner-Mathieu , Jean-Pierre Tignol

We study totally decomposable symplectic and unitary involutions on central simple algebras of index 2 and on split central simple algebras respectively. We show that for every field extension, these involutions are either anisotropic or…

Rings and Algebras · Mathematics 2016-03-03 Andrew Dolphin

An orthogonal involution on a central simple algebra becoming isotropic over any splitting field of the algebra, becomes isotropic over a finite odd degree extension of the base field (provided that the characteristic of the base field is…

Algebraic Geometry · Mathematics 2011-03-15 Nikita A. Karpenko

Over algebraically closed fields of positive characteristic, for simple Lie (super)algebras, and certain Lie (super)algebras close to simple ones, with symmetric root systems (such that for each root, there is minus it of the same…

Representation Theory · Mathematics 2024-09-17 Sofiane Bouarroudj , Pavel Grozman , Alexei Lebedev , Dimitry Leites

We consider the problem of classifying (possibly noncommutative) R-algebras of low rank over an arbitrary base ring R. We first classify algebras by their degree, and we relate the class of algebras of degree 2 to algebras with a standard…

Number Theory · Mathematics 2010-09-08 John Voight

We show that the theories of some (ordered) central simple algebras with involution over real closed fields are model-complete or admit quantifier elimination, and characterize positive cones in terms of morphisms into models of some of…

Logic · Mathematics 2025-03-06 Vincent Astier

We show that a non-hyperbolic orthogonal involution on a central simple algebra over a field of characteristic different from 2 remains non-hyperbolic over some splitting field of the algebra.

Algebraic Geometry · Mathematics 2009-04-21 Nikita A. Karpenko

In this paper, we investigate subnormal subgroups of the multiplicative group of an almost locally simple artinian algebra with involution. In particular, we show that if either the set of traces or the set of norms of such a subgroup with…

Rings and Algebras · Mathematics 2024-03-14 Dau Thi Hue , Huynh Viet Khanh , Bui Xuan Hai

We obtain several restrictions on the terms of the ascending central series of a nilpotent Lie algebra $\mathfrak g$ under the presence of a complex structure $J$. In particular, we find a bound for the dimension of the center of $\mathfrak…

Rings and Algebras · Mathematics 2019-06-05 A. Latorre , L. Ugarte , R. Villacampa

This is a survey of the existing literature, the state of the art, and a few minor new results and open questions regarding the essential dimension of central simple algebras and finite sequences of such algebras over fields whose…

Rings and Algebras · Mathematics 2026-02-09 Adam Chapman , Kelly McKinnie

We study the decomposition of central simple algebras of exponent 2 into tensor products of quaternion algebras. We consider in particular decompositions in which one of the quaternion algebras contains a given quadratic extension. Let $B$…

Rings and Algebras · Mathematics 2013-04-10 Demba Barry

A $3$-fold and a $5$-fold quadratic Pfister forms are canonically associated to every symplectic involution on a central simple algebra of degree $8$ over a field of characteristic $2$. The same construction on central simple algebras of…

K-Theory and Homology · Mathematics 2024-03-26 Jean-Pierre Tignol

For a central simple algebra with a symplectic involution (A,s) over a field of characteristic different from 2, we show that its group of projective similitudes PSim(A,s) is R-trivial in two new cases.

Rings and Algebras · Mathematics 2026-02-27 M. Archita

Generalized Reynolds ideals are ideals of the center of a symmetric algebra over a field of positive characteristic. They have been shown by the second author to be invariant under derived equivalences. In this paper we determine the…

Representation Theory · Mathematics 2008-07-08 Thorsten Holm , Alexander Zimmermann
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