Welcome!!
English version / Japanese version
E-mail :
kfunano[[at]]tohoku.ac.jp, yahoonitaikou[[at]]gmail.com
(Feel free to email me)
Postal address:
Division of Mathematics &
Research Center for Pure and Applied Mathematics
Graduate School of Information Sciences
Tohoku University
6-3-09 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8579, Japan link
Here is my brief curriculum vitae.
Reseach interests
Concentration of measure, Spectral geometry, Convex geometry, and their related topics.
Papers and preprints
In preparation.
(With L. Cavallina, A. Henrot, A. Lemenant, I. Lucardesi, and S. Sakaguchi) Two extremum problems for Neumann eigenvalues, preprint. link (Here is a related slide)
A universal inequality for Neumann eigenvalues of the Laplacian on a convex domain in Euclidean space, Canad. Math. Bull. 67 (2024), no. 1, 222–226.
A note on domain monotonicity for the Neumann eigenvalues of the Laplacian, Illinois J. Math. 67 (2023), no. 4, 677–686.
(With Y. Sakurai) Upper bounds for higher order Poincaré constants, Trans. Amer. Math. Soc. 373 (2020), no. 6, 4415–4436. link
(With Y. Sakurai) Concentration of eigenfunctions of the Laplacian on a closed Riemannian manifold, Proc. Amer. Math. Soc. 147 (2019), no. 7, 3155–3164. link
(With H. Alpert) Macroscopic scalar curvature and areas of cycles. Geom. Funct. Anal. 27 (2017), no. 4, 727–743. link
Applications of the `ham sandwich theorem' to eigenvalues of the Laplacian. Anal. Geom. Metr. Spaces 4 (2016), 317–325. link
Estimates of eigenvalues of the Laplacian by a reduced number of subsets. Israel J. Math. 217 (2017), no. 1, 413–433. link.
Eigenvalues of Laplacian and multi-way isoperimetric constants on weighted Riemannian manifolds, preprint. pdf (Revised at 21th June 2015. A new problem has been added)
(With T. Shioya) Concentration, Ricci curvature, and eigenvalues of Laplacian. Geom. Funct. Anal. 23 (2013), no. 3, 888–936. link
Two infinite versions of the nonlinear Dvoretzky Theorem, Pacific J. Math. 259 (2012), no. 1, 101–108. link
Observable concentration of mm-spaces into Hadamard manifolds, preprint. pdf
Rate of convergence of stochastic processes with values in R-trees and Hadamard manifolds. Osaka J. Math. 47 (2010), no. 4, 911–920. link.
Concentration of maps and group actions. Geom. Dedicata 149 (2010), 103–119. link.
Exponential and Gaussian concentration of 1-Lipschitz maps. Manuscripta Math. 130 (2009), no. 3, 273--285. link
Central and $L_p$-concentration of 1-Lipschitz maps into $R$-trees. J. Math. Soc. Japan 61 (2009), no. 2, 483--506. link
Concentration of 1-Lipschitz maps into an infinite dimensional $\ell_p$-ball with the $\ell_q$-distance function. Proc. Amer. Math. Soc. 137 (2009), no. 7, 2407--2417. link
Estimates of Gromov's box distance. Proc. Amer. Math. Soc. 136 (2008), no. 8, 2911--2920. link
Observable concentration of mm-spaces into spaces with doubling measures. Geom. Dedicata 127 (2007), 49--56. link
Here is a list of my papers in MathSciNet. Most preprints can be found here on the arXiv.
Other articles
Some universal inequalities of eigenvalues and upper bounds for the $L_{\infty}$ norm of eigenfunctions of the Laplacian (survey article) pdf
Book Review “Introduction to coarse geometry (by Tomohiro Fukaya)” (in japanese), Mathematical Sciences, SAIENSU-SHA Co.,Ltd, Jun. 2020. Link
Upper bounds for higher-order Poincar.\'e constants, RIMS kokyuroku No. 2172 (survey article) Link
Ramsey type theorems in geometry (in japanese), Mathematical Sciences, SAIENSU-SHA Co.,Ltd, Dec. 2016. Link