News

Yuya (Ph.D. student) visited IPMU and studied with collaborators.

They worked on a study of how systematic effects caused by asymmetric antenna patterns on satellites change with and without a rotating half-wave plate.

There are still issues to be addressed and we will continue to work on this topic in the future.

From November 25 to 27, Prof. Jo-Yo Ichikura of Nagoya University visited Okayama University to give an intensive lecture and hold a round-table discussion. The lecture was about cosmology and cosmic microwave background radiation, and the discussion session was titled “Measuring Density Fluctuation of the Universe Twice”, which was interesting in that it is possible to test dark energy by CMB observations without assuming uniform isotropy of the Universe.

Yusuke (Ph.D. student) visited the Kavli IPMU, University of Tokyo, to work on the systematic error of LiteBIRD with Prof. Matsumura (Univ. Tokyo) and other CMB researchers at IPMU. Patricia Diego (MPA), who is staying at IPMU, also participated in the discussion and greatly contributed to the study of systematic error theory.

Yusuke is working on a theory for fast estimation and suppression of systematic errors that degrades with CMB polarization observations [Y. Takase et al. 2024, arXiv]. IPMU is responsible for the development of the Polarization Modulator Unit (PMU) on the LiteBIRD low-frequency telescope, which will be used to unify systematic effects originating from the imperfection of the PMU. We discussed with students from Matsumura Lab. an analytical method to treat systematic effects originating from the imperfection of the PMU in a unified manner.

The activity is also introduced in the HP of Kavli IPMU CMB group.

In September, Ms Mami Morinaga from our laboratory completed her Master course.

Simon Madrzyk and Correntin Bourdier (Grenoble INP Phelma, France) have completed their 4-month internship since May. Mami Morinaga, a second-year master’s student, has also completed her master’s thesis after a recent presentation!

Mami authored a master’s thesis in LiteBIRD entitled “Analytical computation of systematic errors of detector gain for CMB full-sky polarization observations”. She conducted research on a method to estimate systematic errors faster than commonly performed time-ordered data analysis by analytically treating systematic errors using advanced mathematics.
She will be employed by a general company in the future, and we look forward to her further success.

Simon and Kiyoshi (2nd year M.S. student) of our lab worked on “Development of Foreground Radiation Removal for CMB Polarization Observation”, and Correntin and Yuya (3rd year Ph.D. student) worked on “Development of High Precision Polarization Light Source” as internship research.

In their final research presentation, they gave a presentation summarizing the results of the four months and deepened the discussion among the lab members. At the end of August, we held a farewell party and had them enjoy Japanese food at an izakaya. We support them both in their future endeavors!

At the request of Prof. Nogami, head of the Department of Physics, Mami Morinaga (2nd year master’s student) who is in our lab wrote an article as a transfer student to Okayama University. The following is a comment from Mami.

I was previously at another private university, but I transferred to Okayama University and gained many valuable experiences.
In particular, I am able to do the cosmology, which I have always wanted to do, here in the Ishino lab.
I hope that those who want to come to Okayama University to study physics (especially those who want to do cosmology) will read this article.

I would like to thank Prof. Nogami, for featuring my transfer experience in this article.

Link to article: Message from a Senior (Mami Morinaga, 2020)

The WPI Site Visit to the International Center for Quantum Field Measurement Systems (QUP) was held on August 5-6, 2024. Ryuji participated in this event as a poster presenter.

In his poster presentation, he gave a detailed explanation of his ongoing research and received valuable comments and advice from many participants. It was a great opportunity to exchange opinions from diverse perspectives and to think about new directions and approaches to research. We intend to use the feedback we received to promote our research in the future.

Okayama University publishes a public relations magazine called “Icho namiki” three times a year, introducing various aspects of Okayama University.

The 106th issue, published in early August 2024, features the activities of Yusuke Takase, a member of our laboratory, and introduces his research and the reason why he decided to pursue a career in universe!
(Click here for the link to Yusuke’s article)

We would like to take this opportunity to thank the writer, photographer, Icho namiki production company, and the University’s PR division for coming to interview him in mid-May, and for their thorough discussions that resulted in a wonderful article. Thank you very much.

The 7th Particle Physics Computing Summer School was held at the KEK for five days from 29 July to 2 August 2024. (For more information on the summer school, click here: URL).

In recent years, research on elementary particles, atomic nuclei, cosmic rays and astrophysics has made great advances with the use of computers. With these developments, mastering the technology is considered essential for future research.

Three members of the Ishino Lab, Kiyoshi, Shunsuke and Mitsuhiro, participated in this school and learnt a lot about cutting-edge technologies such as multivariate analysis and machine learning. Furthermore, 40 students from other universities participated in the school and were able to deepen exchanges.

On the final day, we had the opportunity to present the results of the five days, and we could be able to fully demonstrate the results that we obtained in the school.

Kiyoshi received the presentation award (photo right), and the title of his research was ‘Development of foregrounds removal method for CMB signal extraction using convolutional neural networks’. We will continue to make use of what we learnt at this school and work even harder on our research.

A five-day LiteBIRD collaboration meeting was held at the University of British Colombia (UBC) in Vancouver, Canada, from 15-19/07/24. The climate in Vancouver was pleasant and the environment was very conducive to meetings and discussions.

Hirokazu, Yusuke, Yuya and Kiyoshi participated from Ishino Lab. Hirokazu led the discussion on systematic errors and system requirements. Yusuke explained the scanning strategy and gave talks on systematic errors in a half-wavelength plate and pointings.

Yuya (right picture) presented a poster on beam sidelobe systematic errors and Kiyoshi on foreground removal. Based on the exchange of opinions obtained, we would like to use them for further research promotion.