Results 21 to 30 of about 175,156,885 (130)
A Boothby–Wang Construction in Generalized Contact Geometry
Mathematische Nachrichten, EarlyView.ABSTRACT We establish a generalized analogue of the Boothby–Wang theorem in generalized contact geometry, along with related results. We present a general method for constructing examples of generalized contact structures that are not of Poon–Wade type, and even examples that fail to be generalized contact structures.
Debjit Pal
wiley +1 more source
Graded Differential Polynomial Rings
Mathematische Nachrichten, EarlyView.ABSTRACT We study differential polynomial rings R[t;δ]$R[t;\delta]$ over Γ$\Gamma$‐graded rings, where Γ$\Gamma$ is an arbitrary group. We show that R[t;δ]$R[t;\delta]$ admits a Γ$\Gamma$‐grading compatible with that of R$R$ if and only if δ$\delta$ is a γ$\gamma$‐derivation for some γ∈CΓ(ΓR)$\gamma \in C_\Gamma (\Gamma _R)$, and that this grading is ...
Yassine Ait Mohamed
wiley +1 more source
On Symmetries of Hyperbolic Lattices of Large Rank
Mathematische Nachrichten, EarlyView.ABSTRACT For an even, integral hyperbolic lattice L$L$, the symmetry group of L$L$ is the quotient of the group of positive isometries of L$L$ by the Weyl subgroup of (−2)$(-2)$‐reflections. Following Nikulin, the exceptional lattice of L$L$ is defined as the sublattice generated by elements that have finite orbit under the symmetry group of L$L$.
Torben Grabbel +4 more
wiley +1 more source
An uncomplicated introduction to representational measurement theory
British Journal of Mathematical and Statistical Psychology, EarlyView.Abstract Measurement in psychology is often associated with psychometrics. Despite the theoretical insights afforded by psychometric methods, they represent only a restricted range of possible measurement approaches in the social sciences. Representational measurement theory (RMT) generalizes the logic of measurement developed in the physical sciences ...
Vithor Rosa Franco +3 more
wiley +1 more source
On the additive image of zeroth persistent homology
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract For a category X$X$ and a finite field F$F$, we study the additive image of the functor H0(−;F)∗:rep(X,Top)→rep(X,VectF)$\operatorname{H}_0(-;F)_* \colon \operatorname{rep}(X, \mathbf {Top}) \rightarrow \operatorname{rep}(X, \mathbf {Vect}_F)$, or equivalently, of the free functor rep(X,Set)→rep(X,VectF)$\operatorname{rep}(X, \mathbf {Set ...
Ulrich Bauer +3 more
wiley +1 more source
Fixed points of finite groups acting on generalised Thompson groups
, 2010 We study centralisers of finite order automorphisms of the generalised Thompson groups Fn, ? and conjugacy classes of finite sub- groups in finite extensions of Fn, ?. In particular we show that centralisers of finite automorphisms in Fn, ? are either of
Nucinkis, B.E.A. +2 more
core +1 more source
Rational points on even‐dimensional Fermat cubics
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract We show that even‐dimensional Fermat cubic hypersurfaces are rational over any field of characteristic not equal to three, by constructing explicit rational parameterizations with polynomials of low degree. As a byproduct of our rationality constructions, we obtain estimates for the number of their rational points over a number field and ...
Alex Massarenti
wiley +1 more source
On the automorphisms of the power semigroups of a numerical semigroup
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract If H$H$ is a numerical semigroup (i.e., a cofinite subset of the non‐negative integers closed under addition), then the collection of all non‐empty subsets of H$H$ forms a semigroup P(H)$\mathcal {P}(H)$ under the sumset operation induced by addition in H$H$.
Salvatore Tringali, Kerou Wen
wiley +1 more source
Inner Automorphisms of Finite Semifields [PDF]
, 2010 EnUnlike finite fields, finite semifields possess inner automorphisms. A further surprise is that even noncommutative semifields possess inner automorphisms. We compute inner automorphisms and automorphism groups for semifields quadratic over the nucleus,
Wene , G. P.
core +1 more source
Context‐free graphs and their transition groups
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract Starting from context‐free inverse graphs, we introduce a new class of groups and study their structural properties. We establish closure properties, show that their coword problems are context‐free, analyze torsion elements, and realize them as subgroups of the asynchronous rational group.
Daniele D'Angeli +3 more
wiley +1 more source