11 papers
The Gruenberg-Kegel graph of finite solvable groups that are character-quadratic or semi-rational
Irene Crispi, Sara C. Debón, Emanuele Pacifici +2
A finite group is said to be semi-rational if the set of generators of each cyclic subgroup of is contained in at most two -conjugacy classes. This is equivalent to the…
Gruenberg-Kegel graphs with four edges of finite solvable cut groups
Sara C. Debón, Diego García-Lucas, Ángel del Río
We prove that there is a unique graph with four edges which is the Gruenberg-Kegel graph of a solvable cut group. This contributes to the classification of the Gruenberg-Kegel grap…
Groupoid graded rings and their categories of graded modules
Caio Antony, Ángel del Río
Let be a groupoid acting on a set and let be a -graded ring with graded local units. We study the main properties of the category of -graded -modu…
Uniformly semi-rational groups
Ángel del Río, Marco Vergani
We introduce and study some families of groups whose irreducible characters take values on quadratic extensions of the rationals. We focus mostly on a generalization of inverse sem…
The Gruenberg-Kegel graph of finite solvable rational groups
Sara C. Debón, Diego García-Lucas, Ángel del Río
A finite group is said to be rational if every character of is rational-valued. The Gruenberg-Kegel graph of a finite group is the undirected graph whose vertices are t…
A classification of metacyclic groups by group invariants
Àngel García-Blázquez, Ángel del Río
We obtain a new classification of the finite metacyclic group in terms of group invariants. We present an algorithm to compute these invariants, and hence to decide if two given fi…