About me:
I am a maître de conférences in the Complex Analysis and Geometry group of the IMJ-PRG at Sorbonne Université and a junior member of the Institut Universitaire de France.
Before that, I was in Bonn. First as a post-doctoral fellow at the Max Planck Institute for Mathematics and later as a post-doc in the Geometry group at the University of Bonn, where my mentor was Ursula Hamenstädt.
I did my doctoral studies under the supervision of Hugo Parlier at the Department of Mathematics at the University of Fribourg.
My CV and Publication list.
Address:
Institut de Mathématiques de Jussieu-Paris Rive Gauche
Sorbonne Université - Campus Pierre et Marie Curie
4, place Jussieu - Boite Courrier 247
75252 Paris Cedex 05
France
Office: 16-26 526
E-mail: bram dot petri at imj-prg dot fr
Research
Research interests
Low dimensional geometry and topology, Hyperbolic geometry, Teichmüller and moduli spaces, Random surfaces, Random 3-manifolds, subgroup growth.
Preprints
Accepted articles
| 21. | On Cheeger constants of hyperbolic surfaces |
| | with Thomas Budzinski and Nicolas Curien |
| | Invent. Math., 242, 511 - 530, 2025 |
| | [arXiv version] [Journal version]
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| 20. | The Klein quartic maximizes the multiplicity of the first positive eigenvalue of the Laplacian |
| | with Maxime Fortier Bourque |
| | J. Differential Geom., 128 (2), 521 - 556, 2024. |
| | [arXiv version] [Journal version]
|
| 19. | Statistics of finite degree covers of torus knot complements |
| | with Elizabeth Baker |
| | Ann. H. Lebesgue, 6, 1213 - 1257, 2023. |
| | [arXiv version] [Journal version]
|
| 18. | A model for random three-manifolds |
| | with Jean Raimbault |
| | Comment. Math. Helv., 97 (4), 729 - 768, 2022. |
| | [arXiv version] [Journal version]
|
| 17. | Kissing numbers of regular graphs |
| | with Maxime Fortier Bourque |
| | Combinatorica, 42 (4), 529 - 551, 2022. |
| | [arXiv version] [Journal version]
|
| 16. | Kissing numbers of closed hyperbolic manifolds |
| | with Maxime Fortier Bourque |
| | Amer. J. Math., 144 (4), 1067 - 1085, 2022. |
| | [arXiv version] [Journal version]
|
| 15. | The diameter of random Belyi surfaces |
| | with Thomas Budzinski and Nicolas Curien |
| | Algebr. Geom. Topol., 21: 2929 - 2957, 2021. |
| | [arXiv version] [Journal version]
|
| 14. | On the minimal diameter of closed hyperbolic surfaces |
| | with Thomas Budzinski and Nicolas Curien |
| | Duke Math. J., 170 (2): 365 - 377, 2021. |
| | [arXiv version] [Journal version]
|
| 13. | On distinct finite covers of 3-manifolds |
| | with Stefan Friedl, JungHwan Park, Jean Raimbault and Arunima Ray |
| | Indiana Univ. Math. J., 70 (2): 809 - 846, 2021. |
| | [arXiv version] [Journal version]
|
| 12. | Universality for random surfaces in unconstrained genus |
| | with Thomas Budzinski and Nicolas Curien |
| | Electron. J. Combin., 26 (4): Paper 4.2, 2019 |
| | [arXiv version] [Journal version]
|
| 11. | Subgroup growth of right-angled Artin and Coxeter groups |
| | with Hyungryul Baik and Jean Raimbault |
| | J. Lond. Math. Soc. (2), 101 (2): 556 - 588, 2020. |
| | [arXiv version] [Journal version]
|
| 10. | Subgroup growth of virtually cyclic right-angled Coxeter groups and their free products |
| | with Hyungryul Baik and Jean Raimbault |
| | Combinatorica, 39 (4): 779 - 811, 2019. |
| | [arXiv version] [Journal version]
|
| 9. | Lengths of closed geodesics on random surfaces of large genus |
| | with Maryam Mirzakhani |
| | Comment. Math. Helv., 94 (4): 869 - 889, 2019. |
| | [arXiv version] [Journal version]
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| 8. | Hyperbolic surfaces with long systoles that form a pants decomposition |
| | Proc. Amer. Math. Soc., 146 (3): 1069 - 1081, 2018. |
| | [arXiv version] [Journal version]
|
| 7. | Exponential Torsion Growth for Random 3-Manifolds |
| | with Hyungryul Baik, David Bauer, Ilya Gekhtman, Ursula Hamenstädt, Sebastian Hensel, Thorben Kastenholz and Daniel Valenzuela |
| | Int. Math. Res. Not. IMRN, 21: 6497 - 6534, 2018. |
| | [arXiv version] [Journal version]
|
| 6. | Poisson approximation of the length spectrum of random surfaces |
| | with Christoph Thäle |
| | Indiana Univ. Math. J., 67 (3): 1115 - 1141, 2018. |
| | [arXiv version] [Journal version]
|
| 5. | Mapping class group orbits of curves with self-intersections |
| | with Patricia Cahn and Federica Fanoni |
| | Israel J. Math., 223 (1): 53 - 74, 2018. |
| | [arXiv version] [Journal version]
|
| 4. | Graphs of Large Girth and Surfaces of Large Systole |
| | with Alexander Walker |
| | Math. Res. Lett., 25 (6): 1937 - 1956. 2018. |
| | [arXiv version] [Journal version]
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| 3. | The genus of curve, pants and flip graphs |
| | with Hugo Parlier |
| | Discrete Comput. Geom., 59 (1): 1 - 30, 2018. |
| | [arXiv version] [Journal version]
|
| 2. | Finite length spectra of random surfaces and their dependence on genus |
| | J. Topol. Anal., 09 (4): 649 - 688, 2017. |
| | [arXiv version] [Journal version]
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| 1. | Random regular graphs and the systole of a random surface |
| | J. Topol., 10 (1): 211 - 267, 2017. |
| | [arXiv version] [Journal version]
|
Students
Current:
Hans Mahnig, PhD thesis, Sorbonne University, 2025 - present
Former:
Katia Hadj Said, MSc thesis, Sorbonne University, 2025
Wenxin Jiang, MSc thesis, Sorbonne University, 2025
Co-supervised with Elisha Falbel
Shunan Sun, MSc thesis, Sorbonne University, 2024
Anna Roig Sanchis, PhD thesis, Sorbonne University, 2021 - 2024
Mingkun Liu, PhD thesis, Paris Cité University, 2019 - 2022
Co-supervised with Vincent Delecroix and Anton Zorich
Sofia Amontova, MSc thesis, 2019, University of Bonn
Elizabeth Baker, MSc thesis, 2019, University of Bonn
Muhammad Ardiyansyah, MSc thesis, 2018, University of Bonn
Theses
HDR thesis:
Extremal and random hyperbolic geometry
Defended at the Institut de Mathématiques de Jussieu - Paris Rive Gauche on 21 Feb. 2024.
PhD thesis:
On Random Surfaces
Written under the supervision of Hugo Parlier, University of Fribourg, 2015.
Conference organization
Groups, dynamics and surfaces in Paris, Sep. 17 - 19, 2025
Click here for more information
Arithmetic groups, hyperbolic manifolds and computation, Dec. 9 - 13, 2024
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Random hyperbolic surfaces and random graphs, Nov. 25 - 29, 2024
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Parole aux jeunes chercheuses et chercheurs du RT tétraèdre de platon, Nov. 18 - 20, 2024
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Probability and Geometry in, on and of non-Euclidian spaces, Oct. 2 - 6, 2023
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Geometry and spectra of random hyperbolic surfaces Jun. 12 - 16, 2023
ISM Discovery School
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Groups and Dynamics in Geometry, May 29 - Jun. 2, 2023
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Combinatorics of finite-index subgroups, Nov. 2 - 4, 2022
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Geometric Group Theory in Bonn III, Jan. 31 - Feb. 1, 2019
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Geometric Group Theory in Bonn II, Dec. 3-4, 2015
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Mini course
For the lecture notes of the mini course "Extremal problems and probabilistic methods in hyperbolic geometry", click
here.