Home page of Hisayoshi Toyokawa

Name: Hisayoshi Toyokawa (豊川永喜)

Sex: Male

Date of birth: 18th December 1993

Place of birth: Tokyo

Nationality: Japanese

Present address: Faculty of Engineering, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507, JAPAN

e-mail address: h_toyokawa`at'mail.kitami-it.ac.jp

Ergodic Theory and Random Dynamical Systems, Infinite Ergodic Theory

2018 - 2021: Ph.D., Department of Mathematics, Graduate School of Science, Hokkaido University. (Supervisor: Prof. Michiko Yuri)

2016 - 2018: M.Sc., Department of Mathematics, Graduate School of Science, Hokkaido University. (Supervisor: Prof. Michiko Yuri)

2012 - 2016: B.Sc., Department of Mathematics, Hokkaido University.

2022 - present: Assistant Professor at the faculty of engineering of Kitami Institute of Technology, Japan.

2021 - 2022: Assistant Professor at Institute of Mathematics for Industry of Kyushu University, Japan.

Topological entropy for countable Markov shifts and Exel--Laca algebras, with Yuta Michimoto, Yushi Nakano and Keisuke Yoshida, arXiv preprint.

Conservative and ergodic $\sigma$-finite invariant measures for Markov operators and Darling--Kac law, accepted for publication in Hokkaido Mathematical Journal.
Invariant measures for random piecewise convex maps, with Tomoki Inoue, Nonlinearity, Vol. 37 (2024): 055016.
Finitude of physical measures for random maps, with Pablo G. Barrientos, Fumihiko Nakamura and Yushi Nakano, to appear in Astérisque.
Random invariant densities for Markov operator cocycles and random mean ergodic theorem, with Fumihiko Nakamura, Stochastics and Dynamics, Vol. 24 (2024): 2450009.
Arcsine law for random dynamics with a core, with Fumihiko Nakamura, Yushi Nakano and Kouji Yano, Nonlinearity, Vol. 36 (2023): 1491-1509.
Lyapunov exponents for random maps, with Fumihiko Nakamura and Yushi Nakano, Discrete and Continuous Dynamical Systems Series B, Vol. 27 (2022): 7657-7669.
Mixing and observation for Markov operator cocycles, with Fumihiko Nakamura and Yushi Nakano, Nonlinearity, Vol. 35 (2022): 66-83.
Stability of energy landscape for Ising models, with Bruno Hideki Fukushima-Kimura, Akira Sakai and Yuki Ueda, Physica A, Vol. 583 (2021): 126208.
On the existence of a $\sigma$-finite acim for a random iteration of intermittent Markov maps with uniformly contractive part, Stochastics and Dynamics, Vol. 21 (2021): 2140003.
$\sigma$-finite invariant densities for eventually conservative Markov operators, Discrete and Continuous Dynamical Systems A, Vol. 40 (2020): 2641-2669.

区分的に凸なランダム写像の不変測度について (in Japanese)，井上友喜先生との共著，数理解析研究所講究録 2217 (2022): 127-136.
$\sigma$-finite acims for weakly expanding random maps with uniformly contractive branches, RIMS Kôkyûroku (数理解析研究所講究録) 2181 (2021): 45-51.
On the existence of absolutely continuous $\sigma$-finite invariant measures for random dynamical systems, RIMS Kôkyûroku (数理解析研究所講究録) 2176 (2021): 132-137.
$\sigma$-finite invariant densities for essentially conservative Markov operators via the induced operator (in Japanese), 北海道大学数学講究録 Vol. 176, (2019): 483-490.
Absolutely continuous invariant measures for non-Markov fibred systems deriving from Banach limits, Hokkaido University technical report series in Mathematics (北海道大学数学講究録) Vol. 172, (2018): 56-61.

2020 - present: Hokkaido Dynamical Web Seminar, Organizer
2021: Workshop on Operator Algebras and Dynamical Systems, Organizer
2019 -2020: The 16th Mathematics Conference for Young Researchers, (cancelled due to COVID-19) Representative organizer
2018 - 2019: The 15th Mathematics Conference for Young Researchers, Organizer