activity
20182024
collaborators

6 papers

math.DG2024

Index estimate by first Betti number of minimal hypersurfaces in compact symmetric spaces

Toru Kajigaya, Keita Kunikawa

We show that the Morse index of unstable closed minimal hypersurface in a compact semi-simple Riemannian symmetric space is bounded from below by constant times the fir…

math.DG2021

Liouville theorems for harmonic map heat flow along ancient super Ricci flow via reduced geometry

Keita Kunikawa, Yohei Sakurai

We study harmonic map heat flow along ancient super Ricci flow, and derive several Liouville theorems with controlled growth from Perelman's reduced geometric viewpoint. For non-po…

math.DG2020

Yau and Souplet-Zhang type gradient estimates on Riemannian manifolds with boundary under Dirichlet boundary condition

Keita Kunikawa, Yohei Sakurai

In this paper, on Riemannian manifolds with boundary, we establish a Yau type gradient estimate and Liouville theorem for harmonic functions under Dirichlet boundary condition. Und…

math.DG2020

On Ecker's local integral quantity at infinity for ancient mean curvature flows

Keita Kunikawa

We point out that Ecker's local integral quantity agrees with Huisken's global integral quantity at infinity for ancient mean curvature flows if Huisken's one is finite on each tim…

math.DG2018

Convergence of mean curvature flow in hyperkähler manifolds

Keita Kunikawa, Ryosuke Takahashi

Inspired by the work of Leung-Wan, we study the mean curvature flow in hyperkähler manifolds starting from hyper-Lagrangian submanifolds, a class of middle dimensional submanifolds…

math.DG2018

Remarks on topology of stable translating solitons

Keita Kunikawa, Shunsuke Saito

We show that any complete -stable translating soliton admits no codimension one cycle which does not disconnect . As a corollary, it follows that any two dimensional comp…