Mini Course: Small Points and Bifurcations: Geometry in Families of Rational Maps, Part III

Mini Course: Small Points and Bifurcations: Geometry in Families of Rational Maps, Part III

🎙 Dr. Niki-Myrto Mavraki 👥 2K 📅 July 15, 2026 ⏱ 62 min 👁 588 📄 lecture 🧭 2026-08-15
Available in: English (current) Français

Keywords

small pointsbifurcationrational mapscanonical heightequidistribution

Summary

This is the third and final lecture of a mini-course by Dr. Niki-Myrto Mavraki at the Isaac Newton Institute, part of the programme ‘Complex dynamics: interactions and influences’. The lecture focuses on the geometry of families of rational maps, specifically on the distribution of common preperiodic points and the vanishing of the wedge of invariant currents. The speaker reviews previous results, including the characterization of stability of pairs (f, a) via canonical heights, and introduces a general equidistribution theorem for preperiodic points in families of endomorphisms of projective spaces. This theorem is applied to the study of the ‘unlikely set’ of parameters where two maps have a common periodic point. The main result states that the geometric canonical height of the diagonal vanishes if and only if the pair is isotrivial or the diagonal is preperiodic. The proof uses arithmetic equidistribution and potential theory on Berkovich spaces. The lecture concludes with a discussion of the support of the bifurcation measure and its relation to rigid repelling points, as well as a uniform bound on the number of common periodic points for non-isotrivial pairs.

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Critical Evaluation

Value of the Information & Strength of the Argument

The lecture provides a high-level overview of recent research results, connecting several deep problems in arithmetic and complex dynamics. The argumentation is rigorous, building on previously established theorems and clearly explaining the logical steps. The speaker emphasizes the arithmetic nature of the proofs and the importance of equidistribution techniques. The value lies in the synthesis of multiple results and the presentation of a unified framework for studying unlikely intersections in dynamical systems.

Scientific Rigor, Source Quality, Title Accuracy

The lecture is scientifically rigorous, with clear definitions and statements of theorems. The speaker references several works, including those by Ghioca, Hsia, Tucker, and others, and mentions the recent results by Gauthier and Vigny. The title accurately reflects the content, which is a continuation of a mini-course on small points and bifurcations. The presentation is well-structured, and the speaker handles questions from the audience, demonstrating depth of understanding.

155 words

Title / Content Match

The title accurately reflects the content: the third part of a mini-course on small points and bifurcations in families of rational maps, focusing on geometry and arithmetic equidistribution.

Quality & Reliability

9/10

Lecture by a recognized researcher at a leading mathematical institute, presenting advanced results with rigorous proofs and references to established literature. The content is highly technical and assumes expert audience, but the presentation is clear and precise.

Key Moments

Cited Sources

Concurring Sources

Contribution & Novelties

The lecture presents recent research results on the distribution of common preperiodic points in families of rational maps, connecting arithmetic and complex dynamics. It provides a unified framework via equidistribution and canonical heights, and establishes a criterion for the vanishing of the wedge of invariant currents. The main novelty is the proof of the equivalence between the vanishing of the geometric canonical height of the diagonal and the pair being isotrivial or the diagonal being preperiodic.

Pour aller plus loin :

107 words

Radar Profile

The radar profile shows very high scores in all dimensions, indicating a lecture with substantial information content, high technical depth, and strong reliability. The balance between quantity and quality is excellent, making it a valuable resource for experts.

Reliability 9/10