This dissertation explores two constructions of loop extensions: Schreier extensions of Steiner loops and a new extension formula for right Bol loops arising from Bol reflections.Steiner loops are a key tool in studying Steiner triple systems. We investigate extensions of Steiner loops, focusing in particular on the case of Schreier extensions, which provides a powerful method for constructing Steiner triple systems containing Veblen points. We determine the number of the Steiner triple systems of sizes 19, 27 and 31 with Veblen points, presenting some examples.Furthermore, we study a new extension formula for right Bol loops. We prove the necessary and sufficient conditions for the extension to be right Bol as well. We describe the most important invariants: right multiplication group, nuclei, center. We show that the core is an involutory quandle which is the disjoint union of two isomorphic involutory quandles. Lastly, we derive further results on the structure group of the core of the extension.

Schreier extensions of Steiner loops and extensions of Bol loops arising from Bol reflections

GALICI, MARIO
2024

Abstract

This dissertation explores two constructions of loop extensions: Schreier extensions of Steiner loops and a new extension formula for right Bol loops arising from Bol reflections.Steiner loops are a key tool in studying Steiner triple systems. We investigate extensions of Steiner loops, focusing in particular on the case of Schreier extensions, which provides a powerful method for constructing Steiner triple systems containing Veblen points. We determine the number of the Steiner triple systems of sizes 19, 27 and 31 with Veblen points, presenting some examples.Furthermore, we study a new extension formula for right Bol loops. We prove the necessary and sufficient conditions for the extension to be right Bol as well. We describe the most important invariants: right multiplication group, nuclei, center. We show that the core is an involutory quandle which is the disjoint union of two isomorphic involutory quandles. Lastly, we derive further results on the structure group of the core of the extension.
feb-2024
Inglese
FALCONE, Giovanni
LOMBARDO, Maria Carmela
Università degli Studi di Palermo
Palermo
95
File in questo prodotto:
File Dimensione Formato  
GALICI_tesi_dottorato.pdf

accesso aperto

Dimensione 1.4 MB
Formato Adobe PDF
1.4 MB Adobe PDF Visualizza/Apri

I documenti in UNITESI sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14242/85032
Il codice NBN di questa tesi è URN:NBN:IT:UNIPA-85032