Determining skew left braces of size np

We define the twofold semidirect product of two skew left braces, in which both the additive and multiplicative groups are semidirect products of the corresponding groups of the given skew left braces. We consider an odd prime p and an integer n satisfying ¿¿¿, ¿¿|Aut¿(¿)| for every group E of order...

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Detalles Bibliográficos
Autores: Crespo Vicente, Teresa|||0000-0001-6094-1169, Gil Muñoz, Daniel, Río Doval, Ana|||0000-0003-4785-8760, Vela del Olmo, Maria Montserrat|||0000-0003-0355-9398
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/433629
Acceso en línea:https://hdl.handle.net/2117/433629
https://dx.doi.org/10.1080/00927872.2025.2499066
Access Level:acceso abierto
Palabra clave:Holomorph
Skew brace
Semidirect product
Àrees temàtiques de la UPC::Matemàtiques i estadística::Àlgebra::Aritmètica
Descripción
Sumario:We define the twofold semidirect product of two skew left braces, in which both the additive and multiplicative groups are semidirect products of the corresponding groups of the given skew left braces. We consider an odd prime p and an integer n satisfying ¿¿¿, ¿¿|Aut¿(¿)| for every group E of order n and such that each group of order np has a unique p-Sylow subgroup. Under these conditions, we prove that any skew left brace of size np is either a twofold semidirect product of the trivial brace of size p and a skew left brace of size n or a companion skew left brace of that one. We develop an algorithm to obtain all skew left braces of size np from the skew left braces of size n and provide a formula to count them. We use this result to describe all skew left braces of size 12p for ¿=7, which proves a conjecture of V.G. Bardakov, M.V. Neshchadim and M.K. Yadav.