Results 11 to 20 of about 82 (74)
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)$\operatorname{rep}(X, \mathbf {Set ...
Ulrich Bauer +3 more
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On the automorphisms of the power semigroups of a numerical semigroup
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract If H$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
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Oppenheim–Schur inequalities for causal products
Bulletin of the London Mathematical Society, Volume 58, Issue 6, June 2026.Abstract We establish a class of Oppenheim–Schur‐type inequalities for the convolutional Jury product of positive semidefinite matrices. These results extend the classical Schur and Oppenheim inequalities associated with the Hadamard product to a causal convolutional setting.
Dominique Guillot +2 more
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Infinity‐operadic foundations for embedding calculus
Journal of Topology, Volume 19, Issue 2, June 2026.Abstract Motivated by applications to spaces of embeddings and automorphisms of manifolds, we consider a tower of ∞$\infty$‐categories of truncated right modules over a unital ∞$\infty$‐operad O$\mathcal {O}$. We study monoidality and naturality properties of this tower, identify its layers, describe the difference between the towers as O$\mathcal {O}$
Manuel Krannich, Alexander Kupers
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Thurston norm for coherent right‐angled Artin groups via L2$L^2$‐invariants
Journal of Topology, Volume 19, Issue 2, June 2026.Abstract We define a new notion of splitting complexity for a group G$G$ along a non‐trivial integral character ϕ∈H1(G;Z)$\phi \in H^1(G; \mathbb {Z})$. If G$G$ is a one‐ended coherent right‐angled Artin group, we show that the splitting complexity along an epimorphism ϕ:G→Z$\phi \colon G \rightarrow \mathbb {Z}$ equals the L2$L^2$‐Euler characteristic
Monika Kudlinska
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Twisted ambidexterity in equivariant homotopy theory
Journal of Topology, Volume 19, Issue 2, June 2026.Abstract We develop the concept of twisted ambidexterity in a parametrized presentably symmetric monoidal ∞$\infty$‐category, which generalizes the notion of ambidexterity by Hopkins and Lurie and the Wirthmüller isomorphisms in equivariant stable homotopy theory, and is closely related to Costenoble–Waner duality.
Bastiaan Cnossen
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Algebraic singular functions are not always dense in the ideal of C∗$C^*$‐singular functions
Bulletin of the London Mathematical Society, Volume 58, Issue 5, May 2026.Abstract We give the first examples of étale (non‐Hausdorff) groupoids G$\mathcal {G}$ whose C∗$C^*$‐algebras contain singular elements that cannot be approximated by singular elements in Cc(G)$\mathcal {C}_c(\mathcal {G})$. We provide two examples: one is a bundle of groups and the other a minimal and effective groupoid constructed from a self‐similar
Diego Martínez, Nóra Szakács
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Manifestly unitary higher Hilbert spaces
Journal of the London Mathematical Society, Volume 113, Issue 5, May 2026.Abstract Higher idempotent completion gives a formal inductive construction of the n$n$‐category of finite‐dimensional n$n$‐vector spaces starting with the complex numbers. We propose a manifestly unitary construction of low‐dimensional higher Hilbert spaces, formally constructing the C∗$\mathrm{C}^*$‐3‐category of 3‐Hilbert spaces from Baez's 2 ...
Quan Chen +4 more
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Counting 5‐isogenies of elliptic curves over Q$\mathbb {Q}$
Journal of the London Mathematical Society, Volume 113, Issue 5, May 2026.Abstract We show that the number of 5‐isogenies of elliptic curves defined over Q$\mathbb {Q}$ with naive height bounded by H>0$H > 0$ is asymptotic to C5·H1/6(logH)2$C_5\cdot H^{1/6} (\log H)^2$ for some explicitly computable constant C5>0$C_5 > 0$. This settles the asymptotic count of rational points on the genus zero modular curves X0(m)$\mathcal {X}
Santiago Arango‐Piñeros +3 more
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On the ET0L subgroup membership problem in bounded automata groups
Journal of the London Mathematical Society, Volume 113, Issue 4, April 2026.Abstract We are interested in the subgroup membership problem in groups acting on rooted d$d$‐regular trees and a natural class of subgroups, the stabilisers of infinite rays emanating from the root. These rays, which can also be viewed as infinite words in the alphabet with d$d$ letters, form the boundary of the tree.
Alex Bishop +5 more
wiley +1 more source