Buondì, Mi permetto di consigliare a tutti la presenza a questo seminario. Cantat è uno speaker eccellente. Buno ---------- Forwarded message --------- Da: CRM <crm@sns.it> Date: gio 25 set 2025 alle ore 12:05 Subject: [Junk released by Allowed List] [CENTRO DE GIORGI] -- ANNOUNCEMENT -- COLLOQUIO DE GIORGI - PROF. SERGE CANTAT (October 8th, 2025) To: <crm@sns.it> Cc: <crm@sns.it> *Colloquio De Giorgi* *8* *October** 2025 ore 4:00 pm* Aula Dini, Palazzo del Castelletto, via del Castelletto, Pisa <https://www.google.it/maps/place/Palazzo+del+Castelletto/@43.7183335,10.3983019,17z/data=!3m2!4b1!5s0x12d591a22bb1e129:0xe072bad7e6f06240!4m6!3m5!1s0x12d591fed82b3ffd:0x19eaa5ad348a8846!8m2!3d43.7183297!4d10.4008768!16s%2Fg%2F11ghzn75dy?entry=ttu&g_ep=EgoyMDI1MDUyMS4wIKXMDSoASAFQAw%3D%3D> Prof. *SERGE* *CANTAT* Université de Rennes Title: *Degree Growth * Abstract : Consider a polynomial transformation f of a vector space V and iterate f; that is, compose f with itself, and then with f again, etc. Doing so, one gets a sequence of polynomial transformations f^n. Computing the degree of the formulas defining f^n, one obtains a sequence of integers deg(f^n). The problem I will discuss is : what type of sequences do we obtain in this way? For instance, in dimension 2, the degree of f(x,y)=(y,xy) is 2, then the degree of f^2(x,y)=(xy, xy^2) is 3, then f^3(x,y)=(xy^2,x^2y^3) has degree 5, … and the degree of f^n is given by a sequence which is well known in Pisa. The question is related to dynamical systems, basic algebraic geometry, and some number theory. No previous knowledge will be assumed. *Web site: *https://crmdegiorgi.sns.it/evento/colloquio-de-giorgi-2024-2025/ *The event will take place in person.* Those who are unable to be physically present may attend the talk via zoom by following the link: *https://us02web.zoom.us/j/81126340951?pwd=cUQ2SldDK0xKU3hqdENEU3FiUXNkUT09 <https://us02web.zoom.us/j/81126340951?pwd=cUQ2SldDK0xKU3hqdENEU3FiUXNkUT09>* *Luisa Ferrini* *Centro di Ricerca Matematica* Ennio De Giorgi Palazzo Puteano Piazza <https://www.google.com/maps/search/Piazza+dei+Cavalieri+3?entry=gmail&source=g> <https://www.google.com/maps/search/Piazza+dei+Cavalieri+3?entry=gmail&source=g> dei <https://www.google.com/maps/search/Piazza+dei+Cavalieri+3?entry=gmail&source=g> <https://www.google.com/maps/search/Piazza+dei+Cavalieri+3?entry=gmail&source=g> Cavalieri <https://www.google.com/maps/search/Piazza+dei+Cavalieri+3?entry=gmail&source=g> 3 <https://www.google.com/maps/search/Piazza+dei+Cavalieri+3?entry=gmail&source=g> 56126 PISA