Room 515, Cosmology Bldg., National Taiwan University + Zoom, Physical+Online Seminar

(實體+線上演講 台灣大學次震宇宙館515研討室+ Zoom)

【Time Change】Bijective Cremona Transformations of the Plane

Kuan-Wen Lai (Academia Sinica)

Abstract

Cremona transformations are invertible maps from a projective space to itself defined by polynomials. We say a Cremona transformation is "bijective" if it induces a bijection on the set of rational points. For example, over a finite field, the set of rational points is finite, thus every such transformation induces a permutation in the usual sense, and it is natural to ask whether one can realize all possible permutations among these points this way. In this talk, I will present the answer for projective planes. At least half of this talk is intended for a general audience in mathematics.

This is joint work with Shamil Asgarli, Masahiro Nakahara, and Susanna Zimmermann, published on Selecta Mathematica, New Series 28, 53 (2022).

Link Information:

Zoom ID: 838 7836 1163

Zoom passcode: 714285