1 citations · 5 across the 14 of their papers we have counts for
16 papers
Coarse group theoretic study on stable mixed commutator length
Morimichi Kawasaki, Mitsuaki Kimura, Shuhei Maruyama +2
Let be a group and a normal subgroup of . We study the large scale behavior, not the exact values themselves, of the stable mixed commutator length on the mi…
Invariable generation of certain groups of piecewise projective homeomorphisms of the real line
Shuhei Maruyama
We show that the following groups are invariably generated; the group of piecewise projective homeomorphisms of the real line, the group of piecewise h…
A crossed homomorphism for groups acting on the circle
Shuhei Maruyama
We construct a crossed homomorphism by using a group action on the circle and the Poincaré translation number. We relate it to the Euler class of the action in terms of the Hochsch…
Survey on invariant quasimorphisms and stable mixed commutator length
Morimichi Kawasaki, Mitsuaki Kimura, Shuhei Maruyama +2
A homogeneous quasimorphism on a normal subgroup of is said to be -invariant if for every and for every . Invariant quasimorp…
Invariant quasimorphisms for groups acting on the circle and non-equivalence of SCL
Shuhei Maruyama, Takahiro Matsushita, Masato Mimura
We construct invariant quasimorphisms for groups acting on the circle. Furthermore, we provide a criterion for the non-extendablity of the resulting quasimorphisms and an explicit…
Mixed commutator lengths, wreath products and general ranks
Morimichi Kawasaki, Mitsuaki Kimura, Shuhei Maruyama +2
In the present paper, for a pair of a group and its normal subgroup , we consider the mixed commutator length on the mixed commutator subgroup $[…
Translation numbers for bundle automorphisms and a cocycle on a group of homeomorphisms
Shuhei Maruyama
We introduce and study translation numbers for automorphisms of principal -bundles and flat principal -bundles. We use them to show a vanishing result of a…
The space of non-extendable quasimorphisms
Morimichi Kawasaki, Mitsuaki Kimura, Shuhei Maruyama +2
For a pair of a group and its normal subgroup , we consider the space of quasimorphisms and quasi-cocycles on non-extendable to . To treat this space, we esta…
Group cocycles on the volume-preserving diffeomorphism group
Shuhei Maruyama
We construct two kinds of group cocycles on the volume-preserving diffeomorphism group. We show that, for the volume-preserving diffeomorphism group of the sphere, one of the cocyc…
On boundedness of characteristic class via quasi-morphism
Morimichi Kawasaki, Shuhei Maruyama
In this paper, we characterize the second bounded characteristic classes of foliated bundles in terms of the non-descendible quasi-morphisms on the universal covering of the struct…
The Dixmier-Douady class and an abelian extension of the homeomorphism group
Shuhei Maruyama
Let be a connected topological space and a non-zero cohomology class. A -bundle is a fiber bundle with fiber whose s…
The Dixmier-Douady class, the action homomorphism, and group cocycles on the symplectomorphism group
Shuhei Maruyama
Let be a one-connected and integral symplectic manifold. In this paper, we construct and study a two-cocycle and three-cocycle on the symplectomorphism group of . In particu…
Extensions of quasi-morphisms to the symplectomorphism group of the disk
Shuhei Maruyama
On the group of symplectomorphisms of the disk which are the identity near the boundary, there are homogeneous quasi-morphisms called the Ruelle invarian…
A note on stable commutator length in braided Ptolemy-Thompson groups
Shuhei Maruyama
In this note, we show that the sets of all stable commutator lengths in the braided Ptolemy-Thompson groups are equal to non-negative rational numbers.
The translation number and quasi-morphisms on groups of symplectomorphisms of the disk
Shuhei Maruyama
On groups of symplectomorphisms of the disk, we construct two homogeneous quasi-morphisms which relate to the Calabi invariant and the flux homomorphism respectively. We also show…
The flux homomorphism and central extensions of diffeomorphism groups
Shuhei Maruyama
Let be a 2-dimensional closed unit disk and the group of symplectomorphisms preserving the origin and the boundary pointwise. We consid…