3 citations · 3 across the 2 of their papers we have counts for
4 papers · 1 filter
Quasi-states and symplectic intersections
Michael Entov, Leonid Polterovich
We establish a link between symplectic topology and a recently emerged branch of functional analysis called the theory of quasi-states and quasi-measures. In the symplectic context…
Calabi quasimorphisms for the symplectic ball
Paul Biran, Michael Entov, Leonid Polterovich
We prove that the group of compactly supported symplectomorphisms of the standard symplectic ball admits a continuum of linearly independent real-valued homogeneous quasimorphisms.…
Calabi quasimorphism and quantum homology
Michael Entov, Leonid Polterovich
We prove that the group of area-preserving diffeomorphisms of the 2-sphere admits a non-trivial homogeneous quasimorphism to the real numbers with the following property. Its value…
Commutator length of symplectomorphisms
Michael Entov
Each element of the commutator subgroup of a group can be represented as a product of commutators. The minimal number of factors in such a product is called the commutator length o…