Results 71 to 80 of about 2,016 (201)

Abelian number fields with frobenian conditions

open access: yesMathematika, Volume 72, Issue 4, October 2026.
Abstract We study the distribution of abelian number fields with frobenian conditions imposed on the conductor. In particular, we find an asymptotic for the number of abelian field extensions of a number field k$k$ whose conductor is the sum of two squares. We also discuss an application of the Brauer group of stacks to quadratic number fields.
Julie Tavernier
wiley   +1 more source

Signed Projective Cubes, a Homomorphism Point of View

open access: yesJournal of Graph Theory, Volume 113, Issue 1, Page 38-56, September 2026.
ABSTRACT The (signed) projective cubes, as a special class of graphs closely related to the hypercubes, are on the crossroad of geometry, algebra, discrete mathematics and linear algebra. Defined as Cayley graphs on binary groups, they represent basic linear dependencies.
Meirun Chen   +2 more
wiley   +1 more source

Free semigroups of large critical exponent

open access: yesJournal of Topology, Volume 19, Issue 3, September 2026.
Abstract For a convergence group equipped with an expanding coarse‐cocycle, we construct finitely generated free subsemigroups, which we call Bishop−−Jonessemigroups$\textit{Bishop--Jones semigroups}$, of critical exponent arbitrarily close to but strictly less than the critical exponent of the ambient group.
Aleksander Skenderi
wiley   +1 more source

Surface subgroups for cocompact lattices of isometries of H2n$\mathbb {H}^{2n}$

open access: yesJournal of Topology, Volume 19, Issue 3, September 2026.
Abstract We prove the existence of surface subgroups within any cocompact lattice Γ$\Gamma$ in SO(2n,1)$\mathrm{SO}(2n,1)$ for n⩾2$n\geqslant 2$. This result addresses the cases missing from the work of Hamenstädt in 2015, who constructed surface subgroups in cocompact lattices for all other rank‐1 simple Lie groups of noncompact type.
Jeremy Kahn, Zhenghao Rao
wiley   +1 more source

Determinants from homomorphisms

open access: yesCoRR, 2022
We give a new combinatorial explanation for well-known relations between determinants and traces of matrix powers. Such relations can be used to obtain polynomial-time and poly-logarithmic space algorithms for the determinant. Our new explanation avoids linear-algebraic arguments and instead exploits a classical connection between subgraph and ...
openaire   +4 more sources

Localization sequences for logarithmic topological cyclic homology

open access: yesJournal of Topology, Volume 19, Issue 3, September 2026.
Abstract We introduce the notion of an Ek$\mathbb {E}_k$‐ring with prelogarithmic structure, define logarithmic topological Hochschild homology and logarithmic topological cyclic homology in this context, and establish localization sequences for these theories. Our approach is based on Thom R$R$‐algebras.
John Rognes   +2 more
wiley   +1 more source

FUZZY RINGS AND ITS PROPERTIES

open access: yesJurnal Sains Dasar, 2017
One of algebraic structure that involves a binary operation is a group that is defined  an un empty set (classical) with an associative binary operation, it has identity elements and each element has an inverse. In the structure of the group known as the
Karyati Karyati, Rifki Chandra Utama
doaj  

A Lightweight and Erudite Automated BiLSTM‐Based Multi‐Cycle GAN for Retinal Blood Vessel and Optic Disc Segmentation in Fundus Images

open access: yesEngineering Reports, Volume 8, Issue 8, August 2026.
This graphical abstract presents a lightweight and automated BiLSTM‐based Multi‐Cycle GAN framework for retinal blood vessel and optic disc segmentation in fundus images. Initially, fundus images undergo preprocessing, including green channel extraction, denoising, resizing, and dataset splitting.
Rasmita Kumari Mohanty   +7 more
wiley   +1 more source

Homomorphism Extension

open access: yesCoRR, 2018
We define the Homomorphism Extension (HomExt) problem: given a group $G$, a subgroup $M \leq G$ and a homomorphism $φ: M \to H$, decide whether or not there exists a homomorphism $\widetildeφ: G\to H$ extending $φ$, i.e., $\widetildeφ|_M = φ$. This problem arose in the context of list-decoding homomorphism codes but is also of independent interest ...
openaire   +2 more sources

On Oriented Colourings of Graphs on Surfaces

open access: yesJournal of Graph Theory, Volume 112, Issue 4, Page 357-369, August 2026.
ABSTRACT For an oriented graph G, the least number of colours required to oriented colour G is called the oriented chromatic number of G and denoted χ o ( G ). For a non‐negative integer g let χ o ( g ) be the least integer such that χ o ( G ) ≤ χ o ( g ) for every oriented graph G with Euler genus at most g.
Alexander Clow
wiley   +1 more source

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