Results 51 to 60 of about 241,261 (215)

Automorphisms and Definability (of Reducts) for Upward Complete Structures

open access: yesMathematics, 2022
The Svenonius theorem establishes the correspondence between definability of relations in a countable structure and automorphism groups of these relations in extensions of the structure.
Alexei Semenov, Sergei Soprunov
doaj   +1 more source

Galois cohomology of biquadratic extensions

open access: yesCommentarii Mathematici Helvetici, 1993
Let \(F\) be a field of characteristic different from 2, and let \(\Gamma\) be the Galois group of the separable algebraic closure \(\overline{F}\) over \(F\). Let \(\Lambda\) be the field of two elements, considered as a \(\Gamma\)-module by the trivial action of \(\Gamma\); and if \(K\) is a subfield of \(\overline{F}\) which is a normal, finite ...
Tignol, J.-P., Merkurjev, A.S.
openaire   +1 more source

On the integral simplicial volume of cyclic covers of mapping tori

open access: yesJournal of the London Mathematical Society, Volume 114, Issue 3, September 2026.
Abstract In this paper, we investigate the asymptotic behavior of the integral simplicial volume of cyclic covers of manifolds that fiber over the circle with fiber given by an n$n$‐dimensional torus. By studying the integral filling volume—an invariant introduced by Frigerio and the first author—for the monodromy, we establish both lower and upper ...
Federica Bertolotti   +1 more
wiley   +1 more source

On the notion of indiscernibility in the light of Galois-Grothendieck Theory [PDF]

open access: yes, 2013
We analyze the notion of indiscernibility in the light of the Galois theory of field extensions and the generalization to K-algebras proposed by Grothendieck.
Catren, Gabriel, Page, Julien
core  

On free ring extensions of degree n

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 1981
Nagahara and Kishimoto [1] studied free ring extensions B(x) of degree n for some integer n over a ring B with 1, where xn=b, cx=xρ(c) for all c and some b in B(ρ=automophism of  B), and {1,x…,xn−1} is a basis.
George Szeto
doaj   +1 more source

Interpolation categories for conformal embeddings

open access: yesProceedings of the London Mathematical Society, Volume 133, Issue 3, September 2026.
Abstract In this paper, we give a diagrammatic description of the categories of modules coming from the conformal embeddings V(slN,N)⊂V(soN2−1,1)$\mathcal{V}({\mathfrak{sl}}_{N},N)\subset \mathcal{V}({\mathfrak{so}}_{{N}^{2}-1},1)$. A small variant of this construction (morally corresponding to a conformal embedding of glN${\mathfrak{gl}}_{N}$ level N ...
Cain Edie‐Michell, Noah Snyder
wiley   +1 more source

A History of Selected Topics in Categorical Algebra I: From Galois Theory to Abstract Commutators and Internal Groupoids [PDF]

open access: yesCategories and General Algebraic Structures with Applications, 2016
This paper is a chronological survey, with no proofs, of a direction in categorical algebra, which is based on categorical Galois theory and involves generalized central extensions, commutators, and internal groupoids in Barr exact Mal’tsev and more ...
George Janelidze
doaj  

Groups of generalized G‐type and applications to torsion subgroups of rational elliptic curves over infinite extensions of Q

open access: yesTransactions of the London Mathematical Society, 2019
Recently, there has been much interest in studying the torsion subgroups of elliptic curves base‐extended to infinite extensions of Q. In this paper, given a finite group G, we study what happens with the torsion of an elliptic curve E over Q when ...
Harris B. Daniels   +2 more
doaj   +1 more source

Inducing Coverings on Hilbert Schemes

open access: yesMathematische Nachrichten, Volume 299, Issue 8, Page 2177-2190, August 2026.
ABSTRACT We find an explicit geometric description of all coverings of Hilb2(Σ)$\operatorname{Hilb}^{2}(\Sigma)$ when Σ$\Sigma$ is a normal, complex, quasi‐projective surface with finite fundamental group. We then apply this construction to show that if Σ$\Sigma$ is an irreducible symplectic surface then Hilb2(Σ)$\operatorname{Hilb}^{2}(\Sigma)$ is an ...
Lucas Li Bassi, Filippo Papallo
wiley   +1 more source

Quadratic subfields on quartic extensions of local fields

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 1988
We show that any quartic extension of a local field of odd residue characteristic must contain an intermediate field. A consequence of this is that local fields of odd residue characteristic do not have extensions with Galois group A4 or S4 ...
Joe Repka
doaj   +1 more source

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