activity
20042020
most citedMetrics on a closed surface of genus two which maximize the first eigenvalue of the Laplacian

9 citations · 15 across the 6 of their papers we have counts for

collaborators

6 papers

math.CO2020

Optimal embedding and spectral gap of a finite graph

Takumi Gomyou, Toshimasa Kobayashi, Takefumi Kondo +1

We introduce a new optimization problem regarding embeddings of a graph into a Euclidean space and discuss its relation to the two, mutually dual, optimizations problems introduced…

math.GR2017

Fixed-point property for affine actions on a Hilbert space

Shin Nayatani

Gromov showed that for fixed, arbitrarily large C, any uniformly C-Lipschitz affine action of a random group in his graph model on a Hilbert space has a fixed point. We announce a…

math.DG2017★ 9 cited

Metrics on a closed surface of genus two which maximize the first eigenvalue of the Laplacian

Shin Nayatani, Toshihiro Shoda

In this paper, we settle in the affirmative the Jakobson-Levitin-Nadirashvili-Nigam-Polterovich conjecture, stating that a certain singular metric on the Bolza surface, with area n…

math.DG2013

Quaternionic CR Geometry

Hiroyuki Kamada, Shin Nayatani

Modelled on a real hypersurface in a quaternionic manifold, we introduce a quaternionic analogue of CR structure, called quaternionic CR structure. We define the strong pseudoconve…

math.DG2012★ 4 cited

N-step energy of maps and fixed-point property of random groups

Hiroyasu Izeki, Takefumi Kondo, Shin Nayatani

We prove that a random group of the graph model associated with a sequence of expanders has fixed-point property for a certain class of CAT(0) spaces. We use Gromov's criterion for…

math.DG2004★ 2 cited

Combinatorial harmonic maps and discrete-group actions on Hadamard spaces

Hiroyasu Izeki, Shin Nayatani

We use the combinatorial harmonic map theory to study the isometric actions of discrete groups on Hadamard spaces. Given a finitely generated group acting by automorphisms, properl…