Groups whose character degree graph has diameter three

Let $G$ be a finite group, and let $\Delta(G)$ denote the \emph{prime graph} built on the set of degrees of the irreducible complex characters of $G$. It is well known that, whenever $\Delta(G)$ is connected, the diameter of $\Delta(G)$ is at most $3$. In the present paper, we provide a description of the finite solvable groups for which the diameter of this graph attains the upper bound. This also enables us to confirm a couple of conjectures proposed by M.L. Lewis

Jorge Guillén: viajes a Italia (1953-1959)

Este artículo ofrece por vez primera una crónica detallada de los viajes que Jorge Guillén hizo a Italia entre 1953 y 1959. Las largas estancias del verano de 1954, del verano-otoño de 1955, del otoño-invierno de 1958 y, finalmente, de 1959 se reconstruyen ahora utilizando datos nuevos encontrados en artículos de periódicos y en epistolarios inéditos. Las ciudades descubiertas, los premios recibidos, los encuentros con poetas, críticos y amigos son los sueltos elementos que acompañan al lector en un itinerario dirigido a reconstruir la ampia red de relaciones de las que Guillén disfrutó en Italia y su honda vinculación con este país.This paper offers a first account of Jorge Guillén’s voyages to Italy between 1953 and 1959. Seasonal stays in the Summer of 1954, 1955, Fall and Winter of 1958, and 1959, are rebuilt by using newly found data from newspaper articles and letters. The discovered towns, received awards, meeting with poets, critics and friends, are the loose elements that form the network of Guillén’s relations in Italy and his deep attachment to this country.peerReviewe