Photos by Sugumi Kanno @ Einstein Museum
Our research group explores cosmology and gravitational theory using quantum information theory. We are theoretically investigating fundamental questions such as “How did the universe begin and evolve?” and “Is it possible to unify gravity and quantum theory?”
In cosmology, we focus on primordial gravitational waves generated in the early universe and the nature of dark matter. In gravitational theory, we address foundational problems concerning the consistency between gravity and quantum field theory. (Click here for more details on our research.)
Our group consists of 4 faculty members, 2 doctoral students, 6 master's students, and 4 undergraduate students. (Click here for more details about members.)
Recent News
Our paper appears on arXiv.
Kimihiro Nomura, Akira Taniguchi, Kazushige Ueda
"Violation of the Leggett-Garg inequality in photon-graviton conversion''
Jan 23, 2026
Akira Taniguchi received Outstanding Presentation Award Gold Prize at The 34th Workshop on General Relativity and Gravitation in Japan (JGRG 34).
Tiltle: Quantum nature of gravitational waves from binary black holes and its applications to cosmology
The image is from HP of JGRG 34.
Jan 19 - 23, 2026
Akira Matsumura, Kaito Kashiwagi, Akira Taniguchi, Yuta Uenaga, Kosei Hatakeyama, Ryotaro Fukuzumi, Tomoya Hirotani and Taiki Ikeda gave oral presentations at The 34th Workshop on General Relativity and Gravitation in Japan (JGRG 34) held at Kyoto University.
Our research was featured in the Quantum and Spacetime Research Institute.
Article:Squeezed Light Enhances the Sensitivity of Experiments Probing Gravity-Induced Entanglement
Dec 20, 2025
In the 131st Kyushu Branch Meeting of the Physical Society of Japan held at Sojo University, Takano Taira, Yuta Uenaga and Taiki Ikeda made oral presentations.
Dec 15-17, 2025
Kaito Kashiwagi, Akira Taniguchi, Kosei Hatakeyama, Ryotaro Fukuzumi, Taiki Ikeda, and Kota Fujii made oral presentations in the Quantum and Gravity Meeting 2025.
The image is from HP of the Perspective on Time, Uncertainty and Quantum computation
Kazuhiro Yamamoto talked in the Perspective on Time, Uncertainty and Quantum computation as an invited speaker.
Title: Is Gravity Quantum? − From Thought Experiment to Optomechanical Test −
Our paper appears on arXiv.
Yuka Shiomatsu, Youka Kaku, Akira Matsumura, Tomohiro Fujita
"Boosting Gravity-Induced Entanglement through Parametric Resonance''
Our paper appears on arXiv.
Sugumi Kanno, Jiro Soda, Akira Taniguchi
"Binary gravitational waves as probes of quantum graviton states''
Tomoya Hirotani received the Student Presentation Award of the Physical Society of Japan at the Physical Society of Japan 2025 Annual Meeting.
Tiltle: Oppenheimによる相対論的半古典重力模型で予言される測地線偏差の量子ゆらぎ
The image is from HP of the COSMO-25
Oct 13 - 17, 2025
Akira Taniguchi gave an oral presentation at 28th International Conference on Particle Physics & Cosmology (COSMO-25) held at Carnegie Mellon University, Pittsburgh.
The image is from HP of the Elementary, particles, space, gravity and quantum sensing.
Oct 8 - 10, 2025
In the Elementary, particles, space, gravity and quantum sensing, Akira Matsumura talked as an invited speaker and Akira Taniguchi, Kosei Hatakeyama, Ryotaro Fukuzumi and Taiki Ikeda made oral presentations.
Oct 1, 2025
"Quantum and Spacetime Research Institute" has been founded.
Press Release: https://www.kyushu-u.ac.jp/ja/notices/view/2965
The image is from HP of Research and education at Hiroshima University's Institute of Theoretical Science.
Sep 24, 2025
Kazuhiro Yamamoto talked in the Research and education at Hiroshima University's Institute of Theoretical Science as an invited speaker.
The photo is from HP of The Physical Society of Japan 2025 Annual Meeting
Sep 16 - 19, 2025
Takano Taira, Akira Taniguchi, Yuta Uenaga, Kosei Hatakeyama, Tomoya Hirotani and Ryotaro Fukuzumi talked in The Physical Society of Japan 2025 Annual Meeting.
The image is from HP of 100th Anniversary of Quantum Mechanics
Sep 8 - 12, 2025
In The 100th Anniversary of Quantum Mechanics: The Past and Future of Quantum Fundamentals and Quantum Information, Kanno talked as an invited speaker and Kaito Kashiwagi, Yuta Uenaga, Kosei Hatakeyama Tomoya Hirotani and Ryotaro Fukuzumi presented posters.
The photo is from HP of The 3rd International Workshop on GWEU
Aug 31 - Sep 4, 2025
Sugumi Kanno talked in The 3rd International Workshop on Gravitational Waves and the Early Universe (GWEU25) as an invited speaker.
Our paper appears on arXiv.
Sugumi Kanno, Jiro Soda, Akira Taniguchi
"Quantum nature of gravitational waves from binary black holes''
Our paper appears on arXiv.
Ryotaro Fukuzumi, Kosei Hatakeyama, Daisuke Miki, Kazuhiro Yamamoto
"Free-Particle State Realized via Optimal Filtering in Optomechanics: Implications for Gravity-Induced Entanglement''
Department of Physics, Kyushu University
W1-A-720, 744, Motooka, Nishi-ku, Fukuoka, Japan, 819-0395
Phone: +81-092-802-4101
Fax: +81-092-802-4107