William SAREM

Email: william.sarem@univ-grenoble-alpes.fr
Office 113

PhD student (2023-2026) at Institut Fourier, Grenoble, under the supervision of Pierre Py.
I defended my PhD thesis entitled Stein quotients via Patterson-Sullivan theory and the Shafarevich conjecture on December 2025. Here is the link to the manuscript.

Starting from September 2026, I will be a FSMP post-doc at IMJ-PRG.

My CV (Last update: April 2026).

Publications

Holomorphic functions on geometrically finite quotients of the ball, Journal de l'École Polytechnique — Mathématiques, Tome 13 (2026), pp. 321-348. doi: 10.5802/jep.328. Journal version: pdf.
Curvature properties and Shafarevich conjecture for toroidal compactifications of ball quotients, Journal of Differential Geometry 133 no. 3 (2026), pp. 443-478. doi: 10.4310/jdg/1779982479. arXiv version: 2306.07692.

Research seminar talks

Séminaire de Géométrie Complexe, IMT, Toulouse (April 2026). Entropy, holomorphic convexity, and locally symmetric spaces.
Short talk: Complex analysis Workshop, Oberwolfach (April 2026). Locally symmetric spaces and Stein manifolds
Séminaire Darboux, IMAG, Montpellier (April 2026). Entropie, convexité holomorphe et espaces localement symétriques.
Séminaire Géométrie et Applications, IRMA, Strasbourg (February 2026). Entropy, holomorphic convexity, and locally symmetric spaces.
Séminaire de Géométrie et Topologie, LMBA, Brest (December 2025). Entropie, convexité holomorphe et espaces localement symétriques.
Séminaire de Géométrie et Topologie, IMJ-PRG, Paris (November 2025). Compact analytic subvarieties in quotient spaces.
Séminaire de Géométrie, Groupes et Dynamique, UMPA, Lyon (October 2025). Sous-ensembles analytiques compacts dans des espaces quotients.
Oberseminar (2 x 90min) , Mathematisches Institut, Bayreuth (July 2025). Toroidal compactifications of ball quotients and Shafarevich conjecture.
Short talk: Geometric structures and discrete group actions, CIRM, Marseille (April 2025). Holomorphic properties of ball quotients: towards a higher rank generalization?
Séminaire Géométrie Complexe, IECL, Nancy (March 2025). Propriétés holomorphes des quotients de la boule et exposant critique.
Séminaire Algèbre, Topologie et Géométrie, LJAD, Nice (January 2025). Holomorphic properties of ball quotients.
Séminaire Géométrie Analytique, IRMAR, Rennes (January 2025). Propriétés holomorphes des quotients de la boule.
Séminaire Algèbre et Géométries, Institut Fourier, Grenoble (December 2024). Propriétés holomorphes des quotients de la boule.
Séminaire Géométrie et Topologie, I2M, Marseille (November 2024). Propriétés holomorphes des quotients de la boule par un groupe d'exposant critique petit.
Séminaire Géométrie, IMB, Bordeaux (October 2023). Compactifications toroïdales de quotients de la boule et conjecture de Shafarevich.
Séminaire Algèbre et Géométries, Institut Fourier, Grenoble (October 2023). Conjecture de Shafarevich pour les compactifications toroïdales de quotients de la boule.
Séminaire Géométrie Analytique, IRMAR, Rennes (June 2023). Propriétés de courbure et conjecture de Shafarevich pour les compactifications toroïdales de quotients de la boule.
Short talk: Alpine meeting on nonpositive curvature in Kähler geometry, Aussois (June 2023). Curvature properties for toroidal compactifications of ball quotients.
Séminaire GT3, IRMA, Strasbourg (June 2022). Variétés de Stein et sous-groupes de PU(n,1).

PhD seminar talks

Séminaire Doctorants, UMPA, ENS de Lyon (June 2025). The Poincaré disk, its complex generalization and holomorphic functions.
Séminaire Compréhensible, Institut Fourier, Grenoble (June 2025). The Poincaré disk, its complex generalization and holomorphic functions.
Séminaire Doctorants, IRMA, Strasbourg (March 2025). The Poincaré disk, its complex generalization and holomorphic functions.
Séminaire des doctorants, LMPA, Calais (May 2024). Le disque de Poincaré, sa généralisation complexe et leurs fonctions holomorphes.
Rencontres Doctorales Lebesgue, Angers (April 2024). The complex hyperbolic space and its holomorphic functions.
Séminaire Compréhensible, Institut Fourier, Grenoble (March 2024). The Poincaré disk, its complex generalization and holomorphic functions.
Séminaire Pampers, IRMAR, Rennes, (March 2023). La formule de Matsushima.
Geometry Graduate Colloquium, ETHZ, Zürich (December 2022). Harmonic forms and cohomology in smooth (complex) manifolds.

Research stays

Visiting Benoît Cadorel, IECL, Nancy, 2 months (Jan-Feb 2026).
Visiting Mihai Păun, Mathematisches Institut, Bayreuth, 1 week (July 2025).
Visiting Christian Miebach, ULCO, Calais, 1 week (July 2025).
Visiting Christian Miebach, ULCO, Calais, 3 days (May 2024).
Visiting Simone Diverio, la Sapienza, Rome, 1 week (January 2024).

Attended conferences

Complex Analysis Workshop, Oberwolfach (April 2026).
Geometric structures and discrete group actions, CIRM, Marseille (April 2025).
ANR meeting: L² Invariants, Grenoble (February 2025).
PhD meeting: Rencontres Doctorales Lebesgue, Angers (April 2024).
ERC meeting: Groups of Algebraic Transformations, Rennes (January 2024).
PhD meeting: Parole aux jeunes chercheuses et chercheurs du réseau Platon, Grenoble (November 2023).
Lattices in Negative Curvature, Les Diablerets (July 2023).
Alpine meeting on nonpositive curvature in Kähler geometry, Aussois (June 2023).
Complex Hyperbolic Geometry and Related Topics, CIRM, Marseille (July 2022).

Teaching assistant at the University Grenoble Alpes

Lie Groups and Lattices (Master 2 course), Tutorials, 8h, in English (Fall 2025).
MAT101: Mathematical Language, Elementary Algebra and Geometry (L1 course):
- Lectures and Tutorials, 56h, (Fall 2025).
- Lectures and Tutorials, 32h (Fall 2024).
- Lectures and Tutorials, 32h (Fall 2023).
MAT206: Introduction to Mathematical Biology and Population Dynamics (L1 course):
- Lectures and Tutorials, 32h (Spring 2025).
- Lectures and Tutorials, 32h, in English (Spring 2024).

Responsabilities

PhD students' representative at the doctoral school MSTII.
Organizer of the Séminaire Compréhensible, the PhD seminar of the Fourier Institute (2024-2025).
Organizer of the PhD days of the Fourier Institute consisting in 4 days of talks given by PhD students (2024-2025).

Outreach

(with Victor Issa) À la recherche des triplets pythagoriciens, Image des Maths (May 2021), link.
(with Mathurin Passard) Pratique de la recherche en mathématiques, Journal de Mathématique de l'École, Lyon, special issue (May 2021), link.

Other scientific activities

Reviewer service, zbMATH Open, 2025-present.

Last update: June 2026.