New distinguished classes of spectral spaces: a survey

In the present survey paper, we present several new classes of Hochster's spectral spaces "occurring in nature", actually in multiplicative ideal theory, and not linked to or realized in an explicit way by prime spectra of rings. The general setting is the space of the semistar operations (of finite type), endowed with a Zariski-like topology, which turns out to be a natural topological extension of the space of the overrings of an integral domain, endowed with a topology introduced by Zariski. One of the key tool is a recent characterization of spectral spaces, based on the ultrafilter topology, given in a paper by C. Finocchiaro in Comm. Algebra 2014. Several applications are also discussed

Alcuni problemi di matematica discreta

In questo lavoro vengono illustrati e discussi sei problemi di matematica discreta dati a un grupo di studenti delle ultime classi delle superiori. Oltre alle soluzioni proposte, vengono sviluppate varie osservazioni che offrono spunti per ulteriori sviluppi e collegamenti con altri rami della matematica