Jiayin Pan (潘佳垠)

I am an Assistant Professor at Department of Mathematics, University of California, Santa Cruz.

I work in Riemannian geometry; more precisely, the interplay between Ricci curvature and topology, (equivariant) Gromov-Hausdorff convergence, and Ricci limit spaces. I am also interested in sectional curvature, Lorentzian geometry, and subRiemannian geometry.

I received my Ph.D. degree in 2018 from Rutgers University - New Brunswick, advised by Xiaochun Rong. Before coming to UC Santa Cruz, I was a Visiting Assistant Professor at UC Santa Barbara during AY 18-21, and a Fields Postdoctoral Fellow at Fields Institute during AY 21-22.

Email address: jpan53 at ucsc dot edu or jypan10 at gmail dot com
Office: McHenry 4178
Office hours: (F26) TBD
Pronouns: he/they

Besides mathematics, I enjoy reading election analysis, playing Metroidvania and puzzle games, and hiking.

Selected Research Articles

The articles are listed in the reverse order they were finished and submitted to arXiv. The preprints can be found on arXiv. See CV for full publication list.

(With Dimitri Navarro and Xingyu Zhu)
Nonnegative Ricci curvature and virtual abelianness in dimensions less than 12
(With Dimitri Navarro and Xingyu Zhu)
Complete manifolds with nonnegative Ricci curvature and slow relative volume growth
(With Dimitri Navarro)
Universal non-CD of sub-Riemannian manifolds
To appear in J. Reine Angew. Math. link
(With Dimitri Navarro and Xingyu Zhu)
On the topology of manifolds with nonnegative Ricci curvature and linear volume growth
To appear in J. Eur. Math. Soc. link
(With Zhu Ye)
Nonnegative Ricci curvature, splitting at infinity, and first Betti number rigidity
Adv. Math. 459 (2024) 110028 link
Nonnegative Ricci curvature, nilpotency, and Hausdorff dimension
Math. Ann. 394 (2026) article number 2 link
(With Guofang Wei)
Examples of open manifolds with positive Ricci curvature and non-proper Busemann functions
Amer. J. Math. 148 (2026) 235-246, link
Nonnegative Ricci curvature, metric cones, and virtual abelianness
Geom. & Topol. 28 (2024) 1409–1436 link
(With Guofang Wei)
Examples of Ricci limit spaces with non-integer Hausdorff dimension
Geom. Funct. Anal. 32 (2022) 676-685 link
Nonnegative Ricci curvature and escape rate gap
J. Reine Angew. Math. 782 (2022) 175-196 link
On the escape rate of geodesic loops in an open manifold with nonnegative Ricci curvature
Geom. & Topol. 25 (2021) 1059-1085 link
(With Guofang Wei)
Semi-local simple connectedness of noncollapsing Ricci limit spaces
J. Eur. Math. Soc. 24 (2022) no. 12, 4027-4062 link
Nonnegative Ricci curvature, almost stability at infinity, and structure of fundamental groups
Adv. Math. 474 (2025) 110310 link
Nonnegative Ricci curvature, stability at infinity, and finite generation of fundamental groups
Geom. & Topol. 23 (2019) 3203-3231 link
A Proof of Milnor conjecture in dimension 3
J. Reine Angew. Math. 758 (2020) 253-260 link

Surveys & Notes & Slides

The fundamental groups of open manifolds with nonnegative Ricci curvature
SIGMA 16 (2020), 078, 16 pages (Contribution to Special Issue on Scalar and Ricci Curvature in honor of Misha Gromov on his 75th Birthday) link
(with Guofang Wei)
Universal covers of Ricci limit and RCD spaces
Differential Geometry in the Large, London Mathematical Society Lecture Note Series (463), Cambridge University Press, 2020, Page 352-372 link

Nonnegative Ricci curvature, nilpotency, and asymptotic geometry Video slides

A talk that I gave at SLMath workshop “Recent progress on geometric analysis and Riemannian geometry”.

An Invitation to Gromov-Hausdorff convergence slides

An introductory talk on Gromov-Hausdorff convergence.

Notes on Rong’s cyclicity theorem file

A beautiful theorem by Xiaochun Rong.

Derivatives and Curvature in a nutshell file

Supplemental notes for undergraduate course Classical Differential Geometry.

Non-Euclidean Geometry file

Lecture notes for undergraduate course Non-Euclidean geometry.

Non-academic stuff

A Duck
Selfie (2021)

Keep Calm and Donate to Ukraine

UNITED24
Come Back Alive Foundation
Wild Hornets