Results 51 to 60 of about 145 (141)

The flat cover conjecture for monoid acts

Journal of the London Mathematical Society, Volume 112, Issue 6, December 2025.
Abstract We prove that the Flat Cover Conjecture holds for the category of (right) acts over any right‐reversible monoid S$S$, provided that the flat S$S$‐acts are closed under stable Rees extensions. The argument shows that the class F$\mathcal {F}$‐Mono (S$S$‐act monomorphisms with flat Rees quotient) is cofibrantly generated in such categories ...
Sean Cox
wiley   +1 more source

Computing the bridge length: the key ingredient in a continuous isometry classification of periodic point sets

Acta Crystallographica Section A, Volume 81, Issue 6, Page 427-437, November 2025.
We describe an efficient algorithm to compute the bridge length estimating the size of a complete isoset invariant, which classifies all periodic point sets under Euclidean motion.The fundamental model of any periodic crystal is a periodic set of points at all atomic centres.
Jonathan McManus, Vitaliy Kurlin
wiley   +1 more source

Indiscernibles in monadically NIP theories

Bulletin of the London Mathematical Society, Volume 57, Issue 11, Page 3326-3345, November 2025.
Abstract We prove various results around indiscernibles in monadically NIP theories. First, we provide several characterizations of monadic NIP in terms of indiscernibles, mirroring previous characterizations in terms of the behavior of finite satisfiability. Second, we study (monadic) distality in hereditary classes and complete theories.
Samuel Braunfeld, Michael C. Laskowski
wiley   +1 more source

Asymmetric graphs with quantum symmetry

Proceedings of the London Mathematical Society, Volume 131, Issue 5, November 2025.
Abstract We present an infinite sequence of finite graphs with trivial automorphism group and non‐trivial quantum automorphism group. These are the first known examples of graphs with this property. Moreover, to the best of our knowledge, these are the first examples of any asymmetric classical space that has non‐trivial quantum symmetries.
Josse van Dobben de Bruyn, David E. Roberson, Simon Schmidt   +2 more
wiley   +1 more source

On authomorphisms of extremal type II codes

Revista Integración, 2013
In this article we present some techniques to determine the types of automorphisms of extremal doubly even binary self-dual codes, also called extremal type II codes, with parameters [24, 12, 8], [48, 24, 12] and [120, 60, 24].
Ismael Gutiérrez García, Darwin Villar Salinas   +1 more
doaj  

Symmetric 2‐ ( 35 , 17 , 8 ) Designs With an Automorphism of Order 2

Journal of Combinatorial Designs, Volume 33, Issue 10, Page 399-403, October 2025.
ABSTRACT The largest prime p that can be the order of an automorphism of a 2‐ ( 35 , 17 , 8 ) design is p = 17, and all 2‐ ( 35 , 17 , 8 ) designs with an automorphism of order 17 were classified by Tonchev. The symmetric 2‐ ( 35 , 17 , 8 ) designs with automorphisms of an odd prime order p < 17 were classified in Bouyukliev, Fack and Winne and ...
Sanja Rukavina, Vladimir D. Tonchev
wiley   +1 more source

Longest cycles in vertex‐transitive and highly connected graphs

Bulletin of the London Mathematical Society, Volume 57, Issue 10, Page 2975-2990, October 2025.
Abstract We present progress on three old conjectures about longest paths and cycles in graphs. The first pair of conjectures, due to Lovász from 1969 and Thomassen from 1978, respectively, states that all connected vertex‐transitive graphs contain a Hamiltonian path, and that all sufficiently large such graphs even contain a Hamiltonian cycle.
Carla Groenland, Sean Longbrake, Raphael Steiner, Jérémie Turcotte, Liana Yepremyan   +4 more
wiley   +1 more source

Automorphisms of Codes in the Grassmann Scheme

, 2012
Two mappings in a finite field, the Frobenius mapping and the cyclic shift mapping, are applied on lines in PG($n,p$) or codes in the Grassmannian, to form automorphisms groups in the Grassmanian and in its codes. These automorphisms are examined on two classical coding problems in the Grassmannian.
Etzion, Tuvi, Vardy, Alexander
openaire   +3 more sources

On automorphism groups of polar codes

Over the past years, Polar codes have arisen as a highly effective class of linear codes, equipped with a decoding algorithm of low computational complexity. This family of codes share a common algebraic formalism with the well-known Reed-Muller codes, which involves monomial evaluations. As useful algebraic codes, more specifically known as decreasing
Ma, Jicheng, Yan, Guiying
openaire   +2 more sources