Boundedness of the contactomorphism group for closed contact manifolds
Determine whether, for every closed contact manifold (M,\xi), the contactomorphism group Cont(M,\xi) is bounded with respect to conjugation-invariant norms, i.e., whether Cont(M,\xi) admits no unbounded conjugation-invariant norm. This parallels the known boundedness of the identity component of the diffeomorphism group of a closed manifold.
References
While it is known that the group of diffeomorphisms isotopic to the identity of a closed manifold is bounded , i.e. it does not admit any unbounded conjugation invariant norm, it is still an open question whether a similar statement holds for $Cont(M,\xi)$ of any closed contact manifold $(M,\xi)$.
— Spectral selectors on strongly orderable contact manifolds and applications
(2509.12856 - Arlove, 16 Sep 2025) in Introduction, Subsection 'Applications to the geometry of \widetilde{Cont}(M,\xi)', Subsubsection 'A spectral norm'