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Related papers: Fields with bounded Brauer $2$-torsion index

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Let A be an abelian threefold defined over a number field K with potential multiplication by an imaginary quadratic field M. If A has signature (2,1) and the multiplication by M is defined over an at most quadratic extension, we attach to A…

Number Theory · Mathematics 2025-10-07 Francesc Fité , Pip Goodman

We classify the algebraic combinatorial geometries of arbitrary field extensions of transcendence degree greater than 4 and describe their groups of automorphisms. Our results and proofs extend similar results and proofs by Evans and…

Logic · Mathematics 2009-03-10 Jakub Gismatullin

We provide a characterisation of differentially large fields in arbitrary characteristic and a single derivation in the spirit of Blum axioms for differentially closed fields. In the case of characteristic zero, we use these axioms to…

Algebraic Geometry · Mathematics 2024-12-25 Omar León Sánchez , Marcus Tressl

We study the behavior of square-central elements and Artin-Schreier elements in division algebras of exponent 2 and degree a power of 2. We provide chain lemmas for such elements in division algebras over 2-fields $F$ of cohomological…

Rings and Algebras · Mathematics 2015-04-14 Demba Barry , Adam Chapman

We provide sufficient normal curvature conditions on the boundary of a domain $D \subset \BBR^4$ to guarantee unboundedness of the bilinear Fourier multiplier operator $\T_D$ with symbol $\chi_D$ outside the local $L^2$ setting,…

Classical Analysis and ODEs · Mathematics 2009-07-27 S. Zubin Gautam

It is shown that if $p$ is a complete type of Lascar rank at least 2 over $A$, in the theory of differentially closed fields of characteristic zero, then there exists a pair of realisations, $a_1$ and $a_2$, such that $p$ has a nonalgebraic…

Logic · Mathematics 2022-06-28 James Freitag , Rémi Jaoui , Rahim Moosa

Let $\mathbb{F}_{p^k}$ be a finite field of odd characteristic $p$. In this paper we give a classification, up to isomorphism, of the associative commutative $\mathbb{F}_{p^k}$-algebras, starting from the connection with their bi-brace…

Group Theory · Mathematics 2025-07-09 Riccardo Aragona , Giuseppe Nozzi

A variant of Brauer's induction method is developed. It is shown that quartic p-adic forms with at least 9127 variables have non-trivial zeros, for every p. For odd p considerably fewer variables are needed. There are also subsidiary new…

Number Theory · Mathematics 2014-02-26 D. R. Heath-Brown

It is shown that a contraction on a Hilbert space is complex symmetric if and only if the values of its characteristic function are all symmetric with respect to a fixed conjugation. Applications are given to the description of complex…

Functional Analysis · Mathematics 2007-05-23 Nicolas Chevrot , Emmanuel Fricain , Dan Timotin

It is well known that a purely inseparable field extension $L/F$ with some extra property and degree $[L:F]=4$ determines a Clifford parallelism on the set of lines of the three-dimensional projective space over $F$. By extending the ground…

Algebraic Geometry · Mathematics 2024-02-02 Hans Havlicek

In this paper all two-term tilting complexes over a Brauer tree algebra with multiplicity one are described using a classification of indecomposable two-term partial tilting complexes obtained earlier in a joint paper with M. Antipov. The…

Representation Theory · Mathematics 2013-11-28 Alexandra Zvonareva

Transcendental Brauer elements are notoriously difficult to compute. Work of Wittenberg, and later, Ieronymou, gives a method for computing 2-torsion transcendental classes on surfaces that have a genus 1 fibration with rational 2-torsion…

Algebraic Geometry · Mathematics 2012-02-29 Bianca Viray

An orthogonal involution $\sigma$ on a central simple algebra $A$, after scalar extension to the function field $\mathcal{F}(A)$ of the Severi--Brauer variety of $A$, is adjoint to a quadratic form $q_\sigma$ over $\mathcal{F}(A)$, which is…

Group Theory · Mathematics 2018-07-19 Anne Quéguiner-Mathieu , Jean-Pierre Tignol

We study the universal cover of the complex one-dimensional torus as a model-theoretic structure in a natural language. We consider also abstract covers of one-dimensional tori over algebraically closed fields of characteristic zero. The…

Commutative Algebra · Mathematics 2007-05-23 B. Zilber

Let H be a Hopf algebra of dimension pq over an algebraically closed field of characteristic zero, where p, q are odd primes with p < q < 4p+12. We prove that H is semisimple and thus isomorphic to a group algebra, or the dual of a group…

Quantum Algebra · Mathematics 2012-02-14 Siu-Hung Ng

Homology of the circle with non-trivial local coefficients is trivial. From this well-known fact we deduce geometric corollaries concerning links of codimension two. In particular, the Murasugi-Tristram signatures are extended to invariants…

Geometric Topology · Mathematics 2010-09-08 Oleg Viro

We give a factorization of averages of Borcherds forms over CM points associated to a quadratic form of signature (n,2). As a consequence of this result, we are able to state a theorem like that of Gross and Zagier about which primes can…

Number Theory · Mathematics 2007-05-23 Jarad Schofer

To every object $X$ of a symmetric tensor category over a field of characteristic $p>0$ we attach $p$-adic integers $\text{Dim}_+(X)$ and $\text{Dim}_-(X)$ whose reduction modulo $p$ is the categorical dimension $\text{dim}(X)$ of $X$,…

Representation Theory · Mathematics 2020-05-27 Pavel Etingof , Nate Harman , Victor Ostrik

In [2], an exhaustive construction is achieved for the class of all 4-dimensional unital division algebras over finite fields of odd order, whose left nucleus is not minimal and whose automorphism group contains Klein's four-group. We…

Rings and Algebras · Mathematics 2019-08-20 Ernst Dieterich

We show there is a class of symplectic Lie algebra representations over any field of characteristic not 2 or 3 that have many of the exceptional algebraic and geometric properties of both symmetric three forms in two dimensions and…

Representation Theory · Mathematics 2012-10-23 Marcus J. Slupinski , Robert J. Stanton