Abstract: The purpose of this presentation is to give a brief overview of the birational classification of planar Cremona transformations of degree 3 and 4. The case of cubic planar Cremona transformations is complete in all details and it corrects some results in the previous known classification, namely, it fills some gaps in the classification of Cerveau-Deserti, which by the way has been achieved with different methods. The much more complicated classification of the quartic case is outlined and not illustrated in detail. By using our classifications, we compute exactly the (ordinary) quadratic length of all cubic planar Cremona transformations and, in many cases, also of quartic planar Cremona transformations. The results contained in this talk are part of my Ph.D. Thesis, under the supervision of Professor Alberto Calabri.

Time: 17h30, Thursday, September 24, 2020

Online trên Zoom.

https://us04web.zoom.us/j/74914721760?pwd=L1VOOGEwVHZTb2htejBjUzd6aDlsdz09