C-lab members work on cosmology and a wide range of related research areas in astrophysics in a theoretical way. Our final aim is to make the most accurate theoretical model that describes the Universe.

Cosmology consists in studying essential questions such as what the origin of our world is like and how it evolves today, which have attracted us for a long time. In ancient times it was connected to mythology, religions and philosophy, but now it has also become one of the research fields of science owing to great progress in observational techniques. Modern technology enables us to gain numerous amount of data called “Big Data” and we can obtain a picture of the Universe much more precise than ever. C-lab members try to make this accurate picture of the Universe by computing theoretical models and comparing them with the newest observational data. We also propose new observations based on our theoretical predictions. We hope that our research will lead us to a better understanding of the Universe.

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2024. Apr.
A paper written by Mr. Qi Peng, Assist. Prof. Shuichiro Yokoyama and Prof. Kiyotomo Ichiki was published in General Relativity and Gravitation (link).

2024. Feb.
A paper written by Dr. Xiaolin Liu and Assoc. Prof. Kiyotomo Ichiki was published in Physical Review D (link).

2024. Feb.
Nagoya-Melbourne Joint Research Workshop on Cosmology was held (link).
A total of seven staff and students from the University of Melbourne attended the workshop, and there were lively discussions with us and invited speakers.

2023. Dec.
A paper written by Mr. Kazuya Furusawa (Master student), Assoc. Prof. Hiroyuki Tashiro, Assist. Prof. Shuichiro Yokoyama, and Assoc. Prof. Kiyotomo Ichiki was published in The Astrophysical Journal (link).

2023. Oct.
A paper written by Mr. Keitaro Ishikawa (Master student), Dr. Tomomi Sunayama, Visiting Assoc. Prof. Atsushi J. Nishizawa, Assoc. Prof. Hironao Miyatake, and so on was published in Monthly Notices of the Royal Astronomical Society (link).

2023. Sep.
The paper by Dr. Shun Arai, Assoc. Prof. Hironao Miyatake, and Assist. Prof. Shuichiro Yokoyama (published in April 2023) was featured in JPS Hot Topics.
The article page is here. The Twitter account of JPS Hot Topics is here.

2023. July
The Euclid Space Telescope in which Assoc. Prof. Hironao Miyatake and Dr. Maxime Paillassa participate was successfully launched on July 1st in CEST (link). Miyatake joined the live viewing at Institut d'Astrophysique de Paris (IAP), one of the leading institutes of the Euclid mission. His report can be found at (link).

2023. June
A paper written by Visiting Researchers. Hayato Shimabukuro and Assoc. Prof. Kiyotomo Ichiki was published in Physical Review D (link).

2023. June
There was a 2023 (76th) Physics Department Charter Anniversary Sports Competition. Our laboratory became softball champions(photo) and futsal runners-up. Congratulations!

2023. June
Mr. Yusuke Mikura (Doctoral student) received the Nagoya University Outstanding Graduate Student Award. Congratulations! (link)

2023. June
i-LINK workshop on observational cosmology was held (link).

2023. June
Mr. Eiichiro Komatsu (Director of the Max Planck Institute for Astrophysics) visited our laboratory.

2023. June
Visiting Researchers. Sachiko Kuroyanagi, Mr. Savvas Nesseris, and their group from the Autonomous University of Madrid(UAM) visited our laboratory.

2023. June
A paper written by Assoc. Prof. Kiyotomo Ichiki etc. was published in The Astrophysical Journal Letters (link).

2023. May
A paper written by Mr. Aryab Bansal, Assoc. Prof. Kiyotomo Ichiki, and Assoc. Prof. Hiroyuki Tashiro etc. was published in Monthly Notices of the Royal Astronomical Society (link).

2023. May
A paper written by Dr. Katsuya Abe, Mr. Ryoto Inui (Doctoral student), Assist. Prof. Yuichiro Tada, and Assist. Prof. Shuichiro Yokoyama was published in Journal of Cosmology and Astroparticle Physics (link).

2023. May
A paper written by Mr. Yusuke Mikura (Doctoral student) and Assist. Prof. Yuichiro Tada was published in Journal of Cosmology and Astroparticle Physics (link).

2023. May
A paper written by Mr. Shintaro Hayashi (Doctoral student) and Assoc. Prof. Kiyotomo Ichiki was published in Journal of Cosmology and Astroparticle Physics (link).

2023. May
A paper written by Dr. Hiroto Kondo, Assoc. Prof. Kiyotomo Ichiki, Assoc. Prof. Hiroyuki Tashiro, and Assist. Prof. Kenji Hasegawa was published in Physical Review D (link).

2023. Apr.
A paper written by Postdoctoral Researchers. Shun Arai and Associate Professor Hironao Miyatake etc. was published in Progress of Theoretical and Experimental Physics (link).
PS, in Sep. 2023, this paper was featured in JPS Hot Topics. The article page is here.

2023. Apr.
The results of cosmological analysis with intermediate data from the Subaru Telescope Hyper Suprime-Cam, in which Associate Professor Hironao Miyatake, Visiting Associate Professor Atsushi Nishizawa, and Visiting Researcher Tomomi Sunayama were involved, are released. A webinar was held at midnight on Apr 4 JST and 5 papers were out. Careful analyses of the large-scale structure of the universe reveals that ₈, the clumpiness of the Universe, obtained from measurements of the large-scale structure of the universe is likely to be smaller than S₈ obtained from measurements of the cosmic microwave background radiation from the Planck satellite. This may be a sign that the Standard Model of the Universe is broken. Assoc. Prof. Miyatake led the analysis as a co-chair of the HSC Weak Lensing Working Group. For the press release by Nagoya University, please click here.

2023. Mar.
A paper written by Postdoctoral Researchers. Shun Arai was published in Physical Review D. (link)

2023. Feb.
A paper written by Postdoctoral Researchers. Takahiro S. Yamamoto and Visiting Researchers. Sachiko Kuroyanagi was published in Physical Review D. (link)

2023. Jan.
A paper written by Associate Professor Kiyotomo Ichiki was published in Progress of Theoretical and Experimental Physics. (link)

2022. Aug
A paper written by Postdoctoral Researchers. Takahiro S. Yamamoto and Visiting Researchers. Sachiko Kuroyanagi was published in Physical Review Research. (link)

2022. Aug
A paper by Associate Professor Hironao Miyatake and Visiting Associate Processor Atsushi J. Nishizawa was published in Physical Review Letters (link). The paper was selected as Editors’ Suggestion. The press release by Nagoya University can be found here. This paper was picked up by more than 90 news stories in the world .

2022. July
A paper written by Mr. Yukiyoshi Morishita and Assist. Prof. Shuichiro Yokoyama was published in Journal of Cosmology and Astroparticle Physics. (link)

2022. July
A paper written by Postdoctoral Researchers. Takahiro S. Yamamoto was published in Physical Review D. (link)

2022. May
A paper written by Ms. Hina Sakamoto, Assoc. Prof. Kiyotomo Ichiki and Assist. Prof. Kenji Hasegawa was published in The Astrophysical Journal. (link)

2022. May
A paper written by Mr. Yusuke Mikura (Doctoral student) and Assist. Prof. Yuichiro Tada was published in Journal of Cosmology and Astroparticle Physics.

2022. Apr
A paper written by Assoc. Prof. Hironao Miyatake was published in Physical Review D. (link)

2022. Mar
A paper written by Dr. Yuko Urakawa and Dr. Kazuhiro Kogai was published in Journal of Cosmology and Astroparticle Physics. (link)

2022. Mar.
A paper written by Assoc. Prof. Kiyotomo Ichiki and Mr. Kento Sumiya (Master student) was published in Physical Review D. (link)

2022. Feb.
A paper written by Assoc. Prof. Kiyotomo Ichiki was published in Publications of the Astronomical Society of Japan. (link)

2022. Jan.
Assoc. Prof. Hironao Miyatake was selected for the Fusion Oriented REsearch for disruptive Science and Technology (FOREST) program by the Japan Science and Technology Agency (JST). (link)

2021. Nov.
An article related to cosmological studies by NASA’s next flagship mission Nancy Grace Roman Space Telescope, which is based on papers written by a research group including Assoc. Prof. Hironao Miyatake, appeared in the NASA website. (link)

2021. Oct.
Two papers written by Assoc. Prof. Hironao Miyatake were published in Monthly Notices of the Royal Astronomical Society. In these studies, we forecasted cosmological constraints by a galaxy survey with NASA’s next flagship mission Nancy Grace Roman Space Telescope. (link, link)

2021. Sep.
A paper written by Assoc. Prof. Hironao Miyatake and Lecturer Atsushi J. Nishizawa was published in The Astrophysical Journal. (link)

2021. Aug.
A paper written by Assoc. Prof. Hironao Miyatake and Lecturer Atsushi J. Nishizawa was published in Publications of the Astronomical Society of Japan. In this study, we created a galaxy sample using dark matter maps reconstructed from the Subaru Hyper Suprime-Cam survey data. (link)

2021. June.
A paper written by Mr. Katsuya T. Abe (Doctoral student), Assist. Prof. Yuichiro Tada, and Mr. Ikumi Ueda (Master student) was published in Journal of Cosmology and Astroparticle Physics. (link)

2021. June.
A paper written by Mr. Katsuya T. Abe (Doctoral student) and Assoc. Prof. Hiroyuki Tashiro was published in Physical Review D. (link)

2021. May.
A paper written by Mr. Yusuke Mikura (Master student), Assist. Prof. Yuichiro Tada, and Assist. Prof. Shuichiro Yokoyama was published in Physical Review D. (link)

2021. Mar.
A paper written by Mr. Teppei Minoda (Doctor student), Assoc. Prof. Kiyotomo Ichiki, and Assoc. Prof. Hiroyuki Tashiro was published in Journal of Cosmology and Astroparticle Physics. (link)

2021. Mar.
A paper written by Ms. Mutsumi Minoguchi (Doctor student) and Lecturer Atsushi J. Nishizawa and Prof. Naoshi Sugiyama was published in Monthly Notices of the Royal Astronomical Society. (link)

2021. Mar.
A paper written by Mr. Kazuhiro Kogai (Doctor student) and Dr. Yuko Urakawa was published in Journal of Cosmology and Astroparticle Physics. (link)

2021. Mar.
A paper written by Assist. Prof. Daichi Kashino was published in The Astrophysical Journal. (link)

2021. Mar.
A paper written by Assoc. Prof. Hironao Miyatake was published in The Astrophysical Journal SUPPLEMENT SERIES. (link)

2021.03.23
Ms. Nanaka Yamamoto was selected as an awardee of the best master thesis presentation award.

2021. Mar.
A paper written by Assist. Prof. Shuichiro Yokoyama was published in Journal of Cosmology and Astroparticle Physics. (link)

2021. Mar.
A paper written by Assist. Prof. Takeshi Kobayashi was published in Journal of Cosmology and Astroparticle Physics. (link)

2021.02.26
Assoc. Prof. Kiyotomo Ichiki was selected for the Fusion Oriented REsearch for disruptive Science and Technology (FOREST) program by the Japan Science and Technology Agency (JST) (link)

2021. Jan.
A paper written by Assist. Prof. Shuichiro Yokayama and Dr. Sachiko Kuroyanagi was published in Journal of Cosmology and Astroparticle Physics.(link)

2021. Jan.
A paper written by Assoc. Prof. Hironao Miyatake was published in Monthly Notices of the Royal Astronomical Society. (link)

2021. Mar.
A paper written by Assoc. Prof. Hiroyuki Tashirowas published in Physical Review D. (link)

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Mail Address: ichiki.kiyotomo.a9@f.¥
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