Park Jun-Yong (朴俊勇)

I am a Lecturer and a member of the pure mathematics research group at the University of Sydney.
Previously, I was a research fellow at the University of Melbourne, MPIM Bonn and IBS-CGP Pohang.
I received my Ph.D. in 2018 from the University of Minnesota under the supervision of Craig Westerland.

I'm interested in the arithmetic of algebraic varieties and their moduli spaces. My work focuses on rational points of moduli stacks over function fields (equivalently, families of varieties over curves) and on the height moduli spaces that give the totality of such families a geometry of its own.

"Elliptic curves over k(t), 𝔽_q(t), ℂ(t): Height moduli, exact counts, rank jumps" at Melbourne 2026

Here are my profiles on Google Scholar, MathSciNet, ZbMATH, ORCiD, arXiv and Curriculum Vitæ.

• I am co-organizing a Moduli retreat with Scott Mullane
  Point Counts of Moduli Stacks via Motives and Cohomology
  Time: 1-4 December 2025, Place: Surf Coast, Victoria.
• I am organizing the Spaces, Functions and Numbers Seminar.
  Time: Tuesday 4:30 - 6:00 pm, Place: Macleay Building (A12) Room 301 (SMRI Seminar Room).

• MATH3061: Geometry & Topology.
  The University of Sydney, Fall 2026.
• MATH2069: Discrete Mathematics and Graph Theory.
  The University of Sydney, Spring 2026.
• MATH1062/1023: Math 1B - Multivariable Calculus and Modelling.
  The University of Sydney, Spring 2026.
• Topics in NT: Totality of rational points on moduli stacks - Counting families of varieties.
  KIAS-LFANT Winter School on Number Theory, January 2025.
• MATH1004: Discrete Mathematics.
  The University of Sydney, Fall 2024.
• Topics in AG: Elliptic Surfaces - Classical to Moduli.
  The University of Melbourne, Spring 2023.

• Arithmetic of the moduli of Calabi-Yau fibrations over function fields
• Tate's algorithm via twisted morphisms of abelian surfaces

• Automation Without Understanding: A proof is a product. Understanding is a capacity.
  < Preprint, arXiv, Journal >
• Analytically dense Mordell-Weil rank jumps on elliptic surfaces via transverse realization
  < Preprint, arXiv, Journal >
• 100% of elliptic curves with a marked point have positive rank
  (with Tristan Phillips)
  < Preprint, arXiv, Journal >
• Exact counts of elliptic curves of bounded height over 𝔽_q(t) in characteristics 2 and 3
  < Preprint, arXiv, Journal >
• Height moduli on cyclotomic stacks and counting elliptic curves over function fields
  (with Dori Bejleri and Matthew Satriano)
  < Preprint, arXiv, Journal >
• Étale cohomological stability of the moduli space of stable elliptic surfaces
  (with Oishee Banerjee and Johannes Schmitt)
  < Preprint, arXiv, Journal >
• Arithmetic geometry of the moduli stack of Weierstrass fibrations over ℙ¹
  Mathematische Zeitschrift, Vol. 310, No. 4, #84 (2025) (with Johannes Schmitt)
  < SharedIt, arXiv, Journal >
• Enumerating odd-degree hyperelliptic curves and abelian surfaces over ℙ¹
  Mathematische Zeitschrift, Vol. 304, No. 1, #5 (2023) (with Changho Han)
  < SharedIt, arXiv, Journal >
• Motive of the moduli stack of rational curves on a weighted projective stack
  Research in the Mathematical Sciences, Vol. 8, No. 1, #1 (2021) (with Hunter Spink)
  Special issue of PIMS 2019 Workshop on Arithmetic Topology
  < SharedIt, arXiv, Journal >
• Arithmetic of the moduli of semistable elliptic surfaces
  Mathematische Annalen, Vol. 375, No. 3-4, 1745-1760 (2019) (with Changho Han)
  < SharedIt, arXiv, Journal >
• Unique fiber sum decomposability of genus 2 Lefschetz fibrations
  Topology and its Applications, Vol. 222, 29-52 (2017)
  < arXiv, Journal >
• Lantern substitution and new symplectic 4-manifolds with b₂⁺ = 3
  Mathematical Research Letters, Vol. 21, No. 1, 1-17 (2014) (with Anar Akhmedov)
  < arXiv, Journal >