Papers 【 display / non-display 】

Papers 【 display / non-display 】

• Classifying Extended Higgs Models through the Trilinear Higgs Boson Coupling Measurement at Future Colliders

  Hiroshima, N; Kakizaki, M; Ohzawa, S

  PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2026 ( 2 )   2026.2

  DOI Web of Science

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  Language：The in addition, foreign language   Publishing type：Research paper (scientific journal)   Joint Work  

• Prospects for dark matter observations in dwarf spheroidal galaxies with the Cherenkov Telescope Array Observatory

  Abe, K; Abe, S; Abhir, J; Abhishek, A; Acero, F; Acharyya, A; Adam, R; Aguasca-Cabot, A; Agudo, I; … Show more authors

  MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY   544 ( 3 )   2946 - 2986   2025.12

  DOI Web of Science

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  Language：Japanese   Publishing type：Research paper (scientific journal)   Joint Work  

• Supermassive black holes from inflation constrained by dark matter substructure

  Ando, S; Balaji, S; Fairbairn, M; Hiroshima, N; Ishiwata, K

  PHYSICAL REVIEW D   112 ( 10 )   2025.11

  DOI Web of Science

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  Language：The in addition, foreign language   Publishing type：Research paper (scientific journal)   Joint Work  

• Antihelium-3 sensitivity for the GRAMS experiment

  Zeng, J; Aramaki, T; Aoyama, K; Arai, S; Arai, S; Asaadi, J; Bamba, A; Cannady, N; Coppi, P; De Nol … Show more authors

  ASTROPARTICLE PHYSICS   173   2025.11

  DOI Web of Science

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  Language：Japanese   Publishing type：Research paper (scientific journal)   Joint Work  

• Analytic prescription for t-channel singularities

  Asai, K; Hiroshima, N; Sato, J; Sato, R; Yang, MJS

  PHYSICAL REVIEW D   112 ( 7 )   2025.10

  DOI Web of Science

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  Language：The in addition, foreign language   Publishing type：Research paper (scientific journal)   Joint Work  

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Review Papers 【 display / non-display 】

Review Papers 【 display / non-display 】

• Search for heavy dark matter from dwarf spheroidal galaxies: leveraging cascades and subhalo models

  Deheng Song,Nagisa Hiroshima,Kohta Murase

  Journal of Cosmology and Astroparticle Physics   2024.1  [Reviewed]  [Invited]

  DOI arXiv

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  Language：English   Publishing type：Rapid communication, short report, research note, etc. (scientific journal)   Joint Work  

  The Fermi Large Area Telescope (Fermi-LAT) has been widely used to search for
  Weakly Interacting Massive Particle (WIMP) dark matter signals due to its
  unparalleled sensitivity in the GeV energy band. The leading constraints for
  WIMP by Fermi-LAT are obtained from the analyses of dwarf spheroidal galaxies
  within the Local Group, which are compelling targets for dark matter searches
  due to their relatively low astrophysical backgrounds and high dark matter
  content. In the meantime, the search for heavy dark matter with masses above
  TeV remains a compelling and relatively unexplored frontier. In this study, we
  utilize 14-year Fermi-LAT data to search for dark matter annihilation and decay
  signals in 8 classical dwarf spheroidal galaxies within the Local Group. We
  consider secondary emission caused by electromagnetic cascades of prompt gamma
  rays and electrons/positrons from dark matter, which enables us to extend the
  search with Fermi-LAT to heavier dark matter cases. We also update the dark
  matter subhalo model with informative priors respecting the fact that they
  reside in subhalos of our Milky Way halo aiming to enhance the robustness of
  our results. We place constraints on dark matter annihilation cross section and
  decay lifetime for dark matter masses ranging from $10^3$ GeV to $10^{11}$ GeV,
  where our limits are more stringent than those obtained by many other
  high-energy gamma-ray instruments.

  Other Link： http://arxiv.org/pdf/2401.15606v1

• Dark Matter Search with Cherenkov Telescope Array

  Nagisa Hiroshima

  34th conference in the Rencontres de Blois series   2023.10

  DOI arXiv

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  Language：English   Publishing type：Research paper, summary (international conference)   Single Work  

  Many models of dark matter (DM) are now widely considered and probed
  intensively with accelerators, underground detectors, and astrophysical
  experiments. Among the various approaches, high-energy astrophysical
  observations are extremely useful to complement laboratory searches for some DM
  candidates. In the near future, the Cherenkov Telescope Array (CTA) should
  enable us to access much heavier weakly interacting massive particles, as well
  as a broad range of other DM candidates. In this talk, we describe DM searches
  with CTA.

  Other Link： http://arxiv.org/pdf/2310.01847v1

• Constraining the primordial curvature perturbation using dark matter substructure

  Shin’ichiro Ando,Nagisa Hiroshima,Koji Ishiwata

  Physical Review D   106 ( 10 )   2022.11  [Reviewed]  [Invited]

  DOI arXiv

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  Language：English   Publishing type：Rapid communication, short report, research note, etc. (scientific journal)   Publisher：American Physical Society (APS)   Joint Work  

  Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevD.106.103014/fulltext

• Semi-analytical frameworks for subhaloes from the smallest to the largest scale

  Nagisa Hiroshima,Shin’ichiro Ando,Tomoaki Ishiyama

  Monthly Notices of the Royal Astronomical Society   517 ( 2 )   2728 - 2737   2022.10  [Reviewed]  [Invited]

  DOI arXiv

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  Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Rapid communication, short report, research note, etc. (scientific journal)   Publisher：Oxford University Press (OUP)   Joint Work  

  ABSTRACT
  Substructures of dark matter halo, called subhaloes, provide important clues to understand the nature of dark matter. We construct a useful model to describe the properties of subhalo mass functions based on the well-known analytical prescriptions, the extended Press–Schechter theory. The unevolved subhalo mass functions at arbitrary mass scales become describable without introducing free parameters. The different host halo evolution histories are directly recast to their subhalo mass functions. As applications, we quantify the effects from (i) the Poisson fluctuation, (ii) the host-mass scatter, and the (iii) different tidal evolution models on observables in the current Universe with this scheme. The Poisson fluctuation dominates in the number count of the mass ratio to the host of $\sim {\cal O}(10^{-2})$, where the intrinsic scatter is smaller by a factor of a few. The host-mass scatter around its mean does not affect the subhalo mass function. Different models of the tidal evolution predict a factor of ∼2 difference in numbers of subhaloes with $\lesssim {\cal O}(10^{-5})$, while the dependence of the Poisson fluctuation on the tidal evolution models is subtle. The scheme provides a new tool for investigating the smallest scale structures of our Universe which are to be observed in near future experiments.

  Other Link： https://academic.oup.com/mnras/article-pdf/517/2/2728/46561854/stac2857.pdf

• Impacts of new small-scale N-body simulations on dark matter annihilations constrained from cosmological 21-cm line observations

  Nagisa Hiroshima,Kazunori Kohri,Toyokazu Sekiguchi,Ryuichi Takahashi

  Physical Review D   104 ( 8 )   2021.10  [Reviewed]  [Invited]

  DOI arXiv

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  Authorship：Corresponding author   Language：English   Publishing type：Rapid communication, short report, research note, etc. (scientific journal)   Publisher：American Physical Society (APS)   Joint Work  

  We revisit constraints on annihilating dark matter based on the global 21cm
  signature observed by EDGES. For this purpose, we used the numerical data of
  the latest N-body simulation performed by state-of-the-art standard in order to
  estimate the boost factor at high redshifts ($z$ = 10 - 100), which enhances
  the annihilation of dark matter in course of structure formation. By taking
  into account to what fraction injected energy from dark matter annihilation
  contributes to ionization, excitation and heating of intergalactic medium
  during dark ages, we estimated how large the global 21cm absorption can be. By
  assuming the thermal freezeout scenario, we find that $m_{\rm DM} < 15$ GeV and
  $m_{\rm DM} < 3$ GeV have been excluded at 95$\%$ C.L. for the annihilation
  modes into $b\bar{b}$ and $e^+ e^-$, respectively.

  Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevD.104.083547/fulltext

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Awards 【 display / non-display 】

Awards 【 display / non-display 】

• 公財）富山第一銀行奨学財団賞 奨励賞

  2023.7   富山第一銀行奨学財団  

  Individual or group name of awards：廣島 渚

• The Award for Female Researchers of the University of Toyama

  2021.10   University of Toyama  

  Individual or group name of awards：Nagisa Hiroshima

• Director General Award of KEK Student day

  2016.10   High Energy Accelerator Research Organization, KEK  

  Individual or group name of awards：Nagisa Hiroshima

• 天文・天体物理若手夏の学校 オーラルアワード(重力・宇宙論分科会)

  2014.7   第44回天文・天体物理若手夏の学校   FRBを用いた宇宙論モデルの検証手法

  Individual or group name of awards：廣島渚

• Takekoshi Award

  2013.7   Graduate School of Science, Kyoto University  

  Individual or group name of awards：Nagisa Hiroshima

Grant-in-Aid for Scientific Research 【 display / non-display 】

Grant-in-Aid for Scientific Research 【 display / non-display 】

• 宇宙観測による暗黒物質探査の新展開：解析的暗黒物質ハローモデルを用いた多面的考察

  Grant number：22K14035  2022.4 - 2025.3

  日本学術振興会  科学研究費助成事業  Grant-in-Aid for Early-Career Scientists

  Investigator(s)：廣島　渚

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  Authorship：Principal investigator  Grant type：Competitive

• Multimesseger Study of Heavy Dark Matter

  Grant number：20H05852  2020.11 - 2025.3

  Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Transformative Research Areas (A)

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  Authorship：Coinvestigator(s)  Grant type：Competitive

• Dark matter search unifying theory, gamma-ray and optical observations

  Grant number：19K23446  2019.8 - 2021.3

  Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Research Activity start-up

  Investigator(s)：HIROSHIMA Nagisa

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  Authorship：Principal investigator  Grant type：Competitive

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Other external funds procured 【 display / non-display 】

• 宇宙素粒子物理学に関する研究

  2022.4 - 2023.3

  Local Government  北陸地区国立大学連合 北陸地区国立大学学術研究連携支援

  Investigator(s)：廣島　渚

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  Authorship：Principal investigator 

• ダークマターワーキンググループ

  2019.8 - 2022.12

  Ministry of Public Management, Home Affairs, Posts and Telecommunications  理化学研究所数理創造プログラム ワーキンググループ

  Investigator(s)：廣島　渚

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  Authorship：Principal investigator 

Presentations 【 display / non-display 】

Presentations 【 display / non-display 】

• Dark Matter Halo/Signal/Particle

  Nagisa Hiroshima

  FY2024 "What is dark matter? - Comprehensive study of the huge discovery space in dark matter"  2025.4 

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  Event date： 2025.4

  Language：English   Presentation type：Oral presentation (keynote)  

• CTAO as BSM physics probe

  Nagisa Hiroshima  [Invited]

  The Rencontres du Vietnam on Theory meeting experiments: particle astrophysics and cosmology  2025.1 

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  Event date： 2025.1

  Language：English   Presentation type：Oral presentation (invited, special)  

  Venue：Quy Nhon, Vietnam  

• What can we do to make the invisible visible with cosmic rays?

  Nagisa Hiroshima

  宇宙線冬合宿  2024.12 

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  Event date： 2024.12

  Language：English   Presentation type：Oral presentation (general)  

  Venue：京都  

• Halo as a key to indirect DM searches

  Nagisa Hiroshima  [Invited]

  The International Joint Workshop on the Standard Model and Beyond 2024/3rd Gordon Godfrey Workshop on Astroparticle Physics  2024.12 

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  Event date： 2024.12

  Language：English   Presentation type：Oral presentation (invited, special)  

  Venue：Sydney, Australia  

• Dark matter search from cosmological and astrophysical approaches

  Nagisa Hiroshima  [Invited]

  Joint Seminar  2024.11 

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  Event date： 2024.11

  Language：English   Presentation type：Oral presentation (invited, special)  

  Venue：Ochanomizu University  

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Charge of on-campus class subject 【 display / non-display 】

Charge of on-campus class subject 【 display / non-display 】

• 2026   Advanced particle astrophysics

  Graduate school of Engineering Science

• 2026   High Energy Physics

  College of Engineering Science

Charge of off-campus class subject 【 display / non-display 】

Charge of off-campus class subject 【 display / non-display 】

• 物理学演習B

  2021.10 Institution：富山大学

• 物理学演習A

  2020.10 Institution：富山大学

• 核・素粒子物理学

  2020.4 Institution：富山大学

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  Level：Undergraduate (specialized) 

Social Contribution(Extension lecture) 【 display / non-display 】

Social Contribution(Extension lecture) 【 display / non-display 】

• 暗黒物質の色は何色？ ー 見えないモノを調べる方法 ー

  Role(s)： Lecturer

  (主催) 理化学研究所数理創造プログラム・(共催) アカデミスト株式会社  iTHEMS × academist オンライン一般公開「数理で読み解く科学の世界」  2020.4

• Visibles and Invisibles in the Universe -What is dark matter?-

  Role(s)： Lecturer

  iTHEMS, RIKEN  iTHEMS public lectures at RIKEN Open Day  RIKEN  2019.4

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  Audience： General public

  Type：Lecture

• Towards the discovery of dark matter

  Role(s)： Lecturer

  High Energy Accelerator Research Organization, KEK  KEK Science Cafe  University of Tsukuba Satellite Office, Tsukuba  2018.10

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  Audience： High school students,　University students,　Graduate students,　General public

  Type：Science cafe

Media Coverage 【 display / non-display 】

Media Coverage 【 display / non-display 】

• Live from BELLE-II experiment

  High Energy Accelerator Research Organization, KEK  Dark Matter Day 2018 (Interactions.org )  High Energy Accelerator Research Organization, KEK  2018.10

Academic Activities 【 display / non-display 】

Academic Activities 【 display / non-display 】

• L Science Camp for Female High School Students

  Role(s)： Planning, management, etc.,　Panel moderator, session chair, etc.

  High Energy Accelerator Research Organization, KEK  （ High Energy Accelerator Research Organization, KEK ） 2017.4

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  Type：Other 

  High Energy Accelerator Research Organization, KEK

• Program to inspire female students to study science

  Role(s)： Planning, management, etc.

  Kavli Institute for the Physics and Mathematics of the Universe  （ Kavli Institute for the Physics and Mathematics of the Universe ） 2016.11

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  Kavli Institute for the Physics and Mathematics of the Universe