I'm a researcher in astrophysics working on dark matter detection and the analysis of dwarf spheroidal galaxies. My work focuses on developing novel computational methods to understand dark matter halos and their observational signatures, particularly through stellar kinematics and J-factor estimation.
My research spans both theoretical and observational aspects of dark matter physics. I have extensive experience in developing statistical methods for analyzing stellar data from dwarf galaxies, with particular attention to addressing contamination from foreground stars and improving the robustness of dark matter density profile reconstructions. Recently, I've been working on machine learning approaches to solve the spherical Jeans equation in a model-independent way, using equivariant continuous normalizing flows to estimate stellar phase space densities without relying on traditional parametric models.
I'm also deeply involved in constraining self-interacting dark matter models using kinematic observations of Milky Way satellite galaxies. My work includes developing semi-analytical frameworks like SASHIMI-SIDM that can efficiently model subhalo populations across different dark matter scenarios. Additionally, I investigate particle physics aspects of dark matter, particularly leptophilic WIMP models and their detectability at future collider experiments. Through combining cosmological modeling with observational data analysis, I aim to advance our understanding of dark matter's nature and distribution on galactic and sub-galactic scales.
Publications
JFlow: Model-Independent Spherical Jeans Analysis using Equivariant Continuous Normalizing Flows
Sung Hak Lim, Kohei Hayashi, Shun'ichi Horigome, Shigeki Matsumoto, M. Nojiri
Stringent Constraints on Self-Interacting Dark Matter Using Milky-Way Satellite Galaxies Kinematics
Shin'ichiro Ando, Kohei Hayashi, Shunichi Horigome, M. Ibe, Satoshi Shirai
SASHIMI-SIDM: semi-analytical subhalo modelling for self-interacting dark matter at sub-galactic scales
Shin'ichiro Ando, Shun'ichi Horigome, E. Nadler, Daneng Yang, Hai-Bo Yu
Journal of Cosmology and Astroparticle Physics 2024
Cosmological prior for the
J
-factor estimation of dwarf spheroidal galaxies
Shun'ichi Horigome, Kohei Hayashi, Shin'ichiro Ando
Physical Review D 2022
Leptophilic fermion WIMP: Role of future lepton colliders
Shun'ichi Horigome, Taisuke Katayose, S. Matsumoto, Ipsita Saha
Physical Review D 2021
J-factor estimation of Draco, Sculptor, and Ursa Minor dwarf spheroidal galaxies with the member/foreground mixture model
Shun'ichi Horigome, Kohei Hayashi, M. Ibe, M. Ishigaki, S. Matsumoto, H. Sugai
Foreground effect on the J-factor estimation of ultrafaint dwarf spheroidal galaxies
K. Ichikawa, Shun-ichi Horigome, M. Ishigaki, S. Matsumoto, M. Ibe, H. Sugai, Kohei Hayashi
Monthly notices of the Royal Astronomical Society 2017
Foreground effect on the $J$-factor estimation of classical dwarf spheroidal galaxies
K. Ichikawa, M. Ishigaki, S. Matsumoto, M. Ibe, H. Sugai, Kohei Hayashi, Shun-ichi Horigome