Contact

I am a postdoc at the Institut de Mathématiques de Jussieu at Sorbonne Université, supported by the Swiss National Science Foundation (SNSF). My hosts are Russell Avdek and Vincent Humilière.

Before that I did my PhD under the supervision of Felix Schlenk at the Université de Neuchâtel.

Email:
Johannes dot Hauber at unine dot ch
Address:
Institut de Mathématiques de Jussieu - Paris Rive Gauche (IMJ-PRG)
Sorbonne Université, Bureau 15-25-501
4 place Jussieu, 75005 Paris, France

Research

I work in symplectic topology, with a particular interest in symplectic embedding problems, rational homology balls, and singular Lagrangian submanifolds and their skeleta. I am interested in both quantitative questions, such as symplectic capacities and embedding obstructions, and qualitative questions concerning the rigidity and classification of Lagrangian submanifolds.

Currently I'm thinking a lot about Katok ellipsoids and Vianna tori.

Articles

The Gromov width of Katok ellipsoids
(in preparation)
with Vinicius G. B. Ramos and Felix Schlenk
Lagrangian knotting and the symplectic topology of Lagrangian complements
(in preparation)
with Nikolas Adaloglou
Quantitative symplectic topology of Katok's examples and equivariant symplectic embeddings
arXiv:2609.35209
with Nikolas Adaloglou
The nearby Lagrangian conjecture for pinwheels
arXiv:2605.22473
with Nikolas Adaloglou and Gerard Bargalló i Gómez
Markov staircases
arXiv:2509.03224
with Nikolas Adaloglou, Joé Brendel, Jonny Evans and Felix Schlenk
Pinwheels in symplectic rational and ruled surfaces and non-squeezing of rational homology balls
with Nikolas Adaloglou, arXiv: arXiv:2503.16250;
Journal of Topology (2026) 19 (3).
Semi-Local Exotic Lagrangian Tori in Dimension Four
with Joé Brendel and Joel Schmitz, arXiv:2403.00408;
Annales de l’institut Fourier (online).

Talks

Upcoming Talks

Symplectix seminar (Paris, 02.10.2026)
"Quantitative symplectic topology of Katok's examples"
IMPA (Rio de Janeiro, 25.01.2027–04.02.2027)
Minicourse on smoothings of cyclic quotient singularities and their symplectic topology (with Nikolas Adaloglou)

Past Talks

Unine symplectic working group (Neuchâtel, 22.09.2026)
"Can the superpotential of a torus detect a degeneration in its complement?"
AGNT seminar (Leiden, 17.11.2024)
"Local exotic tori in four dimensional symplectic manifolds"
Symplectic geometry seminar (Berlin, 07.07.2025)
"Symplectic staircases, old and new"
Plane curves and symplectic geometry (Les Marécottes, 21.09.2025)
"Uniqueness of pin-ellipsoid embeddings in CP2"
Oberseminar dynamical systems (Bochum, 25.11.2025)
"Embedding questions of rational homology balls"
Séminaire de topologie, géométrie et algèbre (Nantes, 11.12.2025)
"The symplectic topology of rational homology balls"