Florian Angeletti


Des zippers et des types,

F. Angeletti, Internet, (2021),


Les zippers sont une famille de structures de données qui permettent de représenter concrètement une navigation au sein d'une structure de donnée parente. Un exemple de zipper de liste serait : `1⇒2⇒3⇒4,Ici(5),6⇒7`. Au-delà es listes et des arbres binaires,les choses se compliquent lorsqu'on commence à naviguer dans des types algébriques mutuellement récursifs: le type sous le curseur de navigation dépend du chemin qu'on a pris pour arriver jusqu'à lui. Nous verrons dans cette présentation comment les types algébriques généralisés (GADTs) apportent une solution naturelle à ce problème de dépendance entre donnée et types. De plus cet approche permet d'aborder les-dits GADTs dans un cadre différent des sempiternels interpréteurs de langage jouet.


Extreme events theory,

F. Angeletti, Postdoc research day, Stellenbosch, (2015),


Extreme value theory is a branch of probability theory concerned with extremeevents: events that are very infrequent but can still have major impact on the system at hand. Sportive world records,floods,stock-market crash,species extinction are all examples of these extreme events. Many of these events are exceptional,rule-breaking and thus unpredictable. However,outside of these exceptional scenarii,extreme events follow regular mathematical patterns. These patterns can be used to collect some statistical information on future extreme events by observing carefully ordinary events. Welcome to this session of pattern hunting!


Statistical Physics: A journey through randomness,

F. Angeletti, Postdoc research day, Stellenbosch, (2014),


Have you ever wondered why the world is so unsurprising? At every moment of our life,we are surrounded by earth atmosphere: billions of billions of molecules moving twice as fast as a formula one car. Even if these molecules are really small,their combined energy in a 50m3 room is comparable to the energy released by the detonation of 20 kilograms of TNT. Nevertheless,spontaneous atmospheric explosions does not happen... But why? With billions of billions of particles,writing an equation for every molecule is quite inconvenient. Even if we were able to solve these equations,how could we understand these solutions? The solution of statistical physics is to forget irrelevant details. Starting from simple principles and focusing on meaningful quantities,it is sometimes possible to obtain insightful descriptions of large physical systems. However,finding the right simple principles is an arduous and ongoing task. In this talk,I would present some core ideas of statistical physics and their (un)practical application to everyday life problems : - How common is spontaneous atmospheric asphyxia? - Why should you never fly or time travel when you are lost?