Ryan Unger

Department of Mathematics, Stanford University
Building 380, Stanford, CA 94305
Office 384-E
email: runger [at] stanford [dot] edu




I'm an NSF Postdoc at Stanford University, hosted by Jonathan Luk, and a Miller Fellow at UC Berkeley, hosted by Sung-Jin Oh.
I'm interested in general relativity, nonlinear wave equations, and geometric analysis.
Here is my CV (updated 07/14/24).

I received my PhD at Princeton University in 2024, where I was advised by Mihalis Dafermos.
I received my undergraduate degree at the University of Tennessee, where I was mentored by Alexandre Freire.



Papers

  1. Nonlinear stability of extremal Reissner–Nordström black holes in spherical symmetry (2024)
    with Yannis Angelopoulos and Christoph Kehle
    arXiv:2410.16234
    the arXiv version has bugged figures which have been fixed here

  2. A note on Huisken's isoperimetric mass (2024)
    with Jeff Jauregui and Dan A. Lee
    to appear in Lett. Math. Phys. (arXiv:2408.08871)

  3. Extremal black hole formation as a critical phenomenon (2024)
    with Christoph Kehle
    arXiv:2402.10190

  4. Event horizon gluing and black hole formation in vacuum: the very slowly rotating case (2023)
    with Christoph Kehle
    Advances in Mathematics 452 (2024) (arXiv:2304.08455)

  5. Gravitational collapse to extremal black holes and the third law of black hole thermodynamics (2022)
    with Christoph Kehle
    to appear in J. Eur. Math. Soc. (arXiv:2211.15742)

  6. Noncompact fill-ins of Bartnik data (2022)
    with Dan A. Lee and Martin Lesourd
    J. Geom. Anal. 34:102 (2024) (arXiv:2211.06280)

  7. Density and positive mass theorems for incomplete manifolds (2022)
    with Dan A. Lee and Martin Lesourd
    Calc. Var. Partial Differential Equations 62 (2023) (arXiv:2201.01328)

  8. Density and positive mass theorems for initial data sets with boundary (2021)
    with Dan A. Lee and Martin Lesourd
    Comm. Math. Phys. 395.2 (2022) (arXiv:2112.12017)

  9. The positive mass theorem with arbitrary ends (2021)
    with Martin Lesourd and Shing-Tung Yau
    J. Differential Geom. 128.1 (2024) (arXiv:2103.02744)

  10. Positive scalar curvature on noncompact manifolds and the Liouville theorem (2020)
    with Martin Lesourd and Shing-Tung Yau
    to appear in Comm. Anal. Geom. (arXiv:2009.12618)



Talks

2025 APS meeting, mathematical GR session 2025
Southern California geometric analysis seminar 2025
Caltech analysis seminar 2025
Princeton/IAS joint analysis seminar 2024
Penn State PDE seminar 2024
Cambridge PDE seminar 2024
Stanford Analysis & PDE seminar 2024
UTK geometric analysis seminar 2024
Harvard BHI foundations seminar 2024
MIT string/gravity seminar 2024
EPFL analysis seminar 2024
Columbia analysis seminar 2023
Cretan waves conference 2023
Online mathematical GR and hyperbolic PDE seminar 2023
University of Crete Center for Theoretical Physics 2023
Edinburgh analysis seminar 2023
Oxbridge PDE conference 2023
Rutgers hyperbolic and dispersive PDE seminar 2023
Berkeley analysis seminar 2023
Vanderbilt analysis seminar 2023
Harvard BHI colloquium 2023
Cambridge Friday GR seminar 2023
Zurich mathematical physics & PDE seminar 2022
Imperial College London junior analysis seminar 2022
Texas A&M YMNCGA 2022
Harvard CMSA workshop on scalar curvature and minimal surfaces 2022
Joint Mathematics Meeting special session on scalar curvature and convergence 2022
Johns Hopkins analysis seminar 2021
Harvard CMSA general relativity seminar 2021
Princeton junior general relativity seminar 2021


Miscellaneous

Quanta article on the disproof of the third law of black hole thermodynamics
The extremal collapse threshold and the third law of black hole thermodynamics (PhD thesis)
Event horizon gluing and black hole formation in vacuum: the very slowly rotating case (Oberwolfach Report No. 9/2024)
SLMath summer school on GR and fluids 2024 examples sheets (GR basics, spherical symmetry)


orcid: 0000-0002-9226-303X