22 citations · 80 across the 24 of their papers we have counts for
26 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…
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 $[…
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…
Commuting symplectomorphisms on a surface and the flux homomorphism
Morimichi Kawasaki, Mitsuaki Kimura, Takahiro Matsushita +1
Let be a closed connected oriented surface whose genus is at least two equipped with a symplectic form. Then we show the vanishing of the cup product of the fluxes of c…
Constellations in prime elements of number fields
Wataru Kai, Masato Mimura, Akihiro Munemasa +2
Given any number field, we prove that there exist arbitrarily shaped constellations consisting of pairwise non-associate prime elements of the ring of integers. This result extends…
On the spectrum and linear programming bound for hypergraphs
Sebastian M. Cioabă, Jack H. Koolen, Masato Mimura +2
The spectrum of a graph is closely related to many graph parameters. In particular, the spectral gap of a regular graph which is the difference between its valency and second eigen…
Bavard's duality theorem for mixed commutator length
Morimichi Kawasaki, Mitsuaki Kimura, Takahiro Matsushita +1
Let be a normal subgroup of a group . A quasimorphism on is -invariant if for every and every . The goal in this paper is…
Avoiding a shape, and the slice rank method for a system of equations
Masato Mimura, Norihide Tokushige
Fix a vector space over a finite field and a system of linear equations. We provide estimates, in terms of the dimension of the vector space, of the maximum of the sizes of subsets…
Avoiding a star of three-term arthmetic progressions
Masato Mimura, Norihide Tokushige
We provide an upper bound of the size of a subset A of F_p^n that does not admit a k-star of 3-APs (three-term arithmetic progressions). Namely, the subset A is assumed to contain…
An extreme counterexample to the Lubotzky--Weiss conjecture
Masato Mimura
In 1993, Lubotzky and Weiss conjectured that if a compact group admits two finitely generated dense subgroups, one of which is amenable and the other has Kazhdan's property (T), th…
Amenability versus non-exactness of dense subgroups of a compact group
Masato Mimura
Given a countable residually finite group, we construct a compact group K and two elements w and u of K with the following properties: The group generated by w and the cube of u is…
Group approximation in Cayley topology and coarse geometry, Part II: Fibered coarse embeddings
Masato Mimura, Hiroki Sako
The objective of this series is to study metric geometric properties of disjoint unions of amenable Cayley graphs by group properties of the Cayley accumulation points in the space…
An alternative proof of Kazhdan property for elementary groups
Masato Mimura
In 2010, Invent. Math., Ershov and Jaikin-Zapirain proved Kazhdan's property (T) for elementary groups. This expository article focuses on presenting an alternative simpler proof o…
On strong property (T) and fixed point properties for Lie groups
Tim de Laat, Masato Mimura, Mikael de la Salle
We consider certain strengthenings of property (T) relative to Banach spaces that are satisfied by high rank Lie groups. Let X be a Banach space for which, for all k, the Banach--M…
Strong algebraization of fixed point properties
Masato Mimura
The following natural question arises from Shalom's innovational work (1999, Publ. IHES): "Can we establish an intrinsic criterion to synthesize relative fixed point properties int…
Superrigidity from Chevalley groups into acylindrically hyperbolic groups via quasi-cocycles
Masato Mimura
We prove that every homomorphism from the elementary Chevalley group over a finitely generated unital commutative ring associated with reduced irreducible classical root system of…
Group approximation in Cayley topology and coarse geometry, Part III: Geometric property (T)
Masato Mimura, Narutaka Ozawa, Hiroki Sako +1
In this series of papers, we study correspondence between the following: (1) large scale structure of the metric space bigsqcup_m {Cay(G(m))} consisting of Cayley graphs of finite…
Multi-way expanders and imprimitive group actions on graphs
Masato Mimura
For n at least 2, the concept of n-way expanders was defined by various researchers. Bigger n gives a weaker notion in general, and 2-way expanders coincide with expanders in usual…
Sphere equivalence, Banach expanders, and extrapolation
Masato Mimura
We study the Banach spectral gap lambda_1(G;X,p) of finite graphs G for pairs (X,p) of Banach spaces and exponents. We define the notion of sphere equivalence between Banach spaces…
Group approximation in Cayley topology and coarse geometry, Part I: Coarse embeddings of amenable groups
Masato Mimura, Hiroki Sako
The objective of this series is to study metric geometric properties of (coarse) disjoint unions of amenable Cayley graphs. We employ the Cayley topology and observe connections be…
Property modulo and homomorphism superrigidity into mapping class groups
Masato Mimura
Every homomorphism from finite index subgroups of a universal lattices to mapping class groups of orientable surfaces (possibly with punctures), or to outer automorphism groups of…
Fixed point property for universal lattice on Schatten classes
Masato Mimura
The special linear group G=SL_n(Z[x1,...,xk]) (n at least 3 and k finite) is called the universal lattice. Let n be at least 4, p be any real number in (1,\infty). The main result…