Fumiya Sano's website

I mainly work on inflationary cosmology, especially non-linear effects of cosmological perturbations, using quantum field theory in de Sitter spacetime. I am interested in cosmological approaches to theories beyond the Standard Model (BSM) and the quantum nature of gravity, in addition to the origin of the Universe.

Planck collaboration revealed that slow-roll inflation explains the initial condition of cosmological density perturbations very well at the linear level (i.e., Gaussian level). However, many inflationary models can reproduce the observational result since the linear order is characterized by a free propagation. As a next step, we are now on the stage for exploring "the Standard Model of inflation" by going into interactions of scalar perturbations as well as the linear order of tensor perturbations, which may be read off from near-future observational projects such as LiteBIRD, CMB-S4, and various telescopes for probing large scale structures. Specifically, there has been a growing interest in an approach dabbed as the cosmological collider (CC) program. This program aims to make a theoretical dictionary for BSM particles/interactions appearing in non-Gaussian observational signals. Importantly, because of the possibly high energy scale during inflation, we expect the CC program to be a strong complement to the collider experiments on the ground.

In addition, the inflation serves the irreplacable laboratory for observing primordial metric perturbations containing quantum features of gravity. This observational and bottom-up approach to quantum gravity theories provides an important complementary of theoretical top-down approaches such as string theory. For this purpose, it is necessary as a first step to specify the situation in which the quantumness of the gravitational perturbations remains until observations. Besides the detailed evaluation of the reduced density matrices during inflation performed in previous work, more and more attention is paid to late time evolutions of the quantum fluctuations. In particular, small scale perturbations are to be evaluated as the primary candidate keeping its quantumness. In parallel, the formulation of gravitated quantum measurements for the future experiments are crucial to curve out their quantumness.

My name is Fumiya Sano (佐野 文哉).

I was born and grew up in Yokohama, Japan; I am a Japanese citizen.

My current position is a PhD student at Institute of Science Tokyo (formerly Tokyo Institute of Technology), Tokyo, Japan.

Currently (and probably during my PhD course), I am visiting Cosmology, Gravity and Astroparticle Physics Group, Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS CTPU-CGA), Daejeon, Korea.

• Curriculum Vitae (under construction)

• Papers / Talks / Grants / Teaching

• Email:

sanof.cosmo@gmail.com (main)

sano@ibs.re.kr (IBS)

sano@th.phys.titech.ac.jp (ScienceTokyo)

• Address:   Institute for Basic Science, 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Korea

• InspireHEP:   https://inspirehep.net/authors/2738053 

• IBS CTPU-CGA:   https://ctpu-cga.ibs.re.kr

• ScienceTokyo Cosmology Group:   http://www.th.phys.titech.ac.jp/cosmo/ 

• More info.:   X (Japanese), Facebook

• Apr. 16, 2023–.   Student Research Assistant, hosted by Masahide Yamaguchi. CTPU-CGA, Institute for Basic Science.

• Apr. 1, 2023–Mar. 31, 2026.   JSPS Doctoral Course Research Fellow, hosted by Teruaki Suyama. Institute of Science Tokyo.

• 2023–.   PhD, supervised by Teruaki Suyama and Masahide Yamaguchi. Institute of Science Tokyo.

• 2021–2023.   Master in Physics. Tokyo Institute of Technology.

• 2017–2021.   Bachelor in Physics. Tokyo Institute of Technology.