Dark matter search using the cosmic microwave background

• Project Area: What is dark matter? - Comprehensive study of the huge discovery space in dark matter
• Project/Area Number: 20H05859
• Research Category: Grant-in-Aid for Transformative Research Areas (A)
• Allocation Type: Single-year Grants
• Review Section: Transformative Research Areas, Section (II)
• Research Institution: The University of Tokyo
• Principal Investigator: 小松 英一郎 東京大学, カブリ数物連携宇宙研究機構, 客員上級科学研究員 (00750316)
• Co-Investigator(Kenkyū-buntansha): 白石 希典 公立諏訪東京理科大学, 共通・マネジメント教育センター, 准教授 (00803446)
• Project Period (FY): 2020-11-19 – 2025-03-31
• Project Status: Granted (Fiscal Year 2024)
• Budget Amount: ¥55,250,000 (Direct Cost: ¥42,500,000、Indirect Cost: ¥12,750,000); Fiscal Year 2024: ¥13,000,000 (Direct Cost: ¥10,000,000、Indirect Cost: ¥3,000,000); Fiscal Year 2023: ¥13,000,000 (Direct Cost: ¥10,000,000、Indirect Cost: ¥3,000,000); Fiscal Year 2022: ¥13,000,000 (Direct Cost: ¥10,000,000、Indirect Cost: ¥3,000,000); Fiscal Year 2021: ¥12,350,000 (Direct Cost: ¥9,500,000、Indirect Cost: ¥2,850,000); Fiscal Year 2020: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
• Keywords: ダークマター / 宇宙マイクロ波背景放射 / 偏光 / アクシオン / ベクトル場 / 複屈折効果

Outline of Research at the Start

ダークマターは宇宙に存在する物質の８割を占めるが、その正体は不明である。これまでの研究では、WIMPと呼ばれる弱い相互作用を行う重い粒子が最有力候補であったが、長年の探査にも関わらずその検出は成功していない。そこで、近年は全く異なる種類のダークマター探査が注目されている。本研究では、素粒子物理学の標準理論モデルには含まれない、パリティ対称性を破る「アクシオン場」や、スピンを持つベクトル場などに着目し、それらが宇宙マイクロ波背景放射（CMB）の偏光に与える影響を、理論的・観測的に調べる。CMBの偏光に特化するのが本研究の特色である。

Outline of Annual Research Achievements

パリティ対称性を破るアクシオン場のようなダークマターが光子と相互作用を行うと、光子の偏光面は回転する。これは「宇宙複屈折効果」と呼ばれている。この効果により宇宙マイクロ波背景放射（CMB）の偏光パターンは変化し、EモードとBモード偏光の相互相関（EB相関）が生じる。これは、パリティ対称性を保存する標準的な宇宙モデルでは得られないため、パリティ対称性を破るダークマター探査を可能にする。前年度までの研究では、2020年に発表された欧州宇宙機関（ESA）のCMB観測衛星Planckの高周波検出器（HFI）の最新データを用いてEB相関を測定し、パリティ対称性の破れの兆候を3.3シグマの統計的有意差で観測した。本年度は、この測定の精度を高めるべく、HFIに加えてPlanckの低周波検出器（LFI）とNASAのCMB観測衛星WMAPのデータを同時解析した。その結果、統計的有意差は3.6シグマまで上昇した。100GHz以上の高周波数の光子に感度のあるHFIデータを用いた時は、測定されたEB相関の信号は宇宙複屈折効果ではなく、銀河系の星間ダストの偏光である可能性が指摘されたが、100GHz以下に感度のあるLFIやWMAPの低周波数のデータではダストの影響は無視できる。従って、観測された信号は宇宙複屈折効果で説明できる可能性が高まり、新しい物理の兆候ではないかと注目されている。

Current Status of Research Progress

1: Research has progressed more than it was originally planned.

Reason

パリティ対称性を破る宇宙複屈折効果が確認されれば、標準的な宇宙モデルを超える新しい物理現象の発見となる。そのような結果は大きなインパクトを持つため、本計画研究で初めてその兆候が捉えられたEB相関の信号が、本当に宇宙複屈折効果によるものかどうかを判定するのは重要である。本年度の研究では、これまでの解析でまだ使っていなかったPlanckのLFIの最新データと、Planck以前のCMB観測衛星であるWMAPのデータのEB相関を解析に加えることで、観測された信号の起源を精査した。その結果、さらに統計的に有意な結果を得た。これは予想を大きく上回る成果であり、本計画研究は、当初計画していた以上のペースで進展している。

Strategy for Future Research Activity

観測されたEB相関の信号を、パリティ対称性を破るアクシオン場のようなダークマターとCMB光子との相互作用で説明する際、これまで広く使われてきたEB相関の理論予言は不十分な近似に基づいていたことがわかった。そこで今後は、ボルツマン方程式をきちんと解いて得た正しい理論予言を測定結果と比較し、EB相関を説明するアクシオン場の背後にある物理現象を探る予定である。また、将来的な観測により、宇宙の再結合期（赤方偏移で約1090）で生成されたCMBの偏光だけでなく、赤方偏移の小さな近傍宇宙の電離ガスから生成された新しいCMB偏光のEB相関が測定可能か、そしてそれがアクシオン場の物理にどのような情報をもたらすのかを調べる予定である。

Research Products

• [Int'l Joint Research] Max Planck Institute for Astrophysics/Ludwig Maximilian University of Munich(ドイツ)
• [Int'l Joint Research] University of Oslo(ノルウェー)
• [Int'l Joint Research] University of Cambridge(英国)
• [Int'l Joint Research] Czech Academy of Sciences(チェコ)
• [Int'l Joint Research] University of Pittsburgh/Stony Brook University/University of Illinois Urbana-Champaign(米国)
• [Int'l Joint Research]
• [Int'l Joint Research] Max Planck Institute for Astrophysics(ドイツ)
• [Int'l Joint Research] Paris-Saclay University/University of Toulouse/University of Paris(フランス)
• [Int'l Joint Research] University of Cambridge/University of Oxford/Cardiff University(英国)
• [Int'l Joint Research] University of Oslo(ノルウェー)
• [Int'l Joint Research] Universidad de Cantabria(スペイン)
• [Int'l Joint Research]
• [Int'l Joint Research] Max-Planck-Institut fuer Astrophysik(ドイツ)
• [Int'l Joint Research] University of Portsmouth(英国)
• [Int'l Joint Research] University of New South Wales(オーストラリア)
• [Int'l Joint Research] Instituto de Fisica Teorica UAM/CSIC(スペイン)
• [Int'l Joint Research] ASIAA(台湾)
• [Journal Article] Impact of anisotropic birefringence on measuring cosmic microwave background lensing (2023)
  • Author(s): Cai Hongbo、Guan Yilun、Namikawa Toshiya、Kosowsky Arthur
  • Journal Title: Physical Review D Volume: 107 Issue: 4 Pages: 043513-043513
  • DOI: 10.1103/physrevd.107.043513
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Isotropic cosmic birefringence from early dark energy (2023)
  • Author(s): Murai Kai、Naokawa Fumihiro、Namikawa Toshiya、Komatsu Eiichiro
  • Journal Title: Physical Review D Volume: 107 Issue: 4
  • DOI: 10.1103/physrevd.107.l041302
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Cosmic birefringence tomography and calibration independence with reionization signals in the CMB (2023)
  • Author(s): Sherwin Blake D、Namikawa Toshiya
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 520 Issue: 3 Pages: 3298-3304
  • DOI: 10.1093/mnras/stac3146
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Is cosmic birefringence due to dark energy or dark matter? A tomographic approach (2022)
  • Author(s): Nakatsuka Hiromasa、Namikawa Toshiya、Komatsu Eiichiro
  • Journal Title: Physical Review D Volume: 105 Issue: 12 Pages: 123509-123509
  • DOI: 10.1103/physrevd.105.123509
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Lattice simulations of Abelian gauge fields coupled to axions during inflation (2022)
  • Author(s): Caravano Angelo、Komatsu Eiichiro、Lozanov Kaloian D.、Weller Jochen
  • Journal Title: Physical Review D Volume: 105 Issue: 12 Pages: 123530-123530
  • DOI: 10.1103/physrevd.105.123530
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] New physics from the polarized light of the cosmic microwave background (2022)
  • Author(s): Komatsu Eiichiro
  • Journal Title: Nature Reviews Physics Volume: 4 Issue: 7 Pages: 452-469
  • DOI: 10.1038/s42254-022-00452-4
  • Peer Reviewed
• [Journal Article] New constraints on axion-gauge field dynamics during inflation from Planck and BICEP/Keck data sets (2022)
  • Author(s): Paolo Campeti, Ogan Ozsoy, Ippei Obata, Maresuke Shiraishi
  • Journal Title: JCAP Volume: 07 Issue: 07 Pages: 1-32
  • DOI: 10.1088/1475-7516/2022/07/039
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Cosmic birefringence from monodromic axion dark energy (2022)
  • Author(s): Silvia Gasparotto, Ippei Obata
  • Journal Title: JCAP Volume: 08 Issue: 08 Pages: 1-19
  • DOI: 10.1088/1475-7516/2022/08/025
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Improved constraints on cosmic birefringence from the WMAP and Planck cosmic microwave background polarization data (2022)
  • Author(s): Eskilt Johannes R.、Komatsu Eiichiro
  • Journal Title: Physical Review D Volume: 106 Issue: 6 Pages: 063503-063503
  • DOI: 10.1103/physrevd.106.063503
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Implications of the cosmic birefringence measurement for the axion dark matter search (2022)
  • Author(s): Obata Ippei
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2022 Issue: 09 Pages: 062-062
  • DOI: 10.1088/1475-7516/2022/09/062
  • Peer Reviewed / Open Access
• [Journal Article] Assessment of the RFI by the X-Band Antenna in LiteBIRD Using a 3D Electromagnetic Field Simulator (2022)
  • Author(s): Tsuji M.、Tsujimoto M.、Sekimoto Y.、Dotani T.、Shiraishi M.
  • Journal Title: Journal of Low Temperature Physics Volume: 209 Issue: 5-6 Pages: 1097-1103
  • DOI: 10.1007/s10909-022-02889-4
  • Peer Reviewed
• [Journal Article] Can primordial parity violation explain the observed cosmic birefringence? (2022)
  • Author(s): Fujita Tomohiro、Minami Yuto、Shiraishi Maresuke、Yokoyama Shuichiro
  • Journal Title: Physical Review D Volume: 106 Issue: 10 Pages: 1-1
  • DOI: 10.1103/physrevd.106.103529
  • Peer Reviewed
• [Journal Article] Finding evidence for inflation and the origin of galactic magnetic fields with CMB surveys (2022)
  • Author(s): Mandal Sayan、Sehgal Neelima、Namikawa Toshiya
  • Journal Title: Physical Review D Volume: 105 Issue: 6 Pages: 063537-063537
  • DOI: 10.1103/physrevd.105.063537
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Simons Observatory: Constraining inflationary gravitational waves with multitracer <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>-mode delensing (2022)
  • Author(s): T. Namikawa, Y. Chinone (11/28), O. Tajima (28/35), et al.
  • Journal Title: Physical Review D Volume: 105 Issue: 2 Pages: 023511-023511
  • DOI: 10.1103/physrevd.105.023511
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Axion-gauge field dynamics with backreaction (2022)
  • Author(s): Ishiwata Koji、Komatsu Eiichiro、Obata Ippei
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2022 Issue: 03 Pages: 010-010
  • DOI: 10.1088/1475-7516/2022/03/010
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Cosmic Birefringence from the <i>Planck</i> Data Release 4 (2022)
  • Author(s): Diego-Palazuelos P.、Eskilt J.?R.、Minami Y.、Tristram M.、Sullivan R.?M.、Banday A.?J.、Barreiro R.?B.、Eriksen H.?K.、G?rski K.?M.、Keskitalo R.、Komatsu E.、Mart?nez-Gonz?lez E.、Scott D.、Vielva P.、Wehus I.?K.
  • Journal Title: Physical Review Letters Volume: 128 Issue: 9 Pages: 091302-091302
  • DOI: 10.1103/physrevlett.128.091302
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Gravitational wave trispectrum in the axion-SU(2) modelGravitational wave trispectrum in the axion-SU(2) model (2022)
  • Author(s): Tomohiro Fujita, Kai Murai, Ippei Obata and Maresuke Shiraishi
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 01 Issue: 01 Pages: 007-007
  • DOI: 10.1088/1475-7516/2022/01/007
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The isotropic attractor solution of axion-SU(2) inflation: universal isotropization in Bianchi type-I geometry (2021)
  • Author(s): Wolfson Ira、Maleknejad Azadeh、Murata Tomoaki、Komatsu Eiichiro、Kobayashi Tsutomu
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2021 Issue: 09 Pages: 031-031
  • DOI: 10.1088/1475-7516/2021/09/031
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Constraining reionization with the first measurement of the cross-correlation between the CMB optical-depth fluctuations and the Compton y-map (2021)
  • Author(s): Namikawa Toshiya、Roy Anirban、Sherwin Blake D.、Battaglia Nicholas、Spergel David N.
  • Journal Title: Physical Review D Volume: 104 Issue: 6 Pages: 063514-063514
  • DOI: 10.1103/physrevd.104.063514
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Axion dark matter search using arm cavity transmitted beams of gravitational wave detectors (2021)
  • Author(s): Koji Nagano, Hiromasa Nakatsuka, Soichiro Morisaki, Tomohiro Fujita, Yuta Michimura, Ippei Obata
  • Journal Title: Physical Review D Volume: 104 Issue: 6 Pages: 62008-62008
  • DOI: 10.1103/physrevd.104.062008
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] CMB mode coupling with isotropic polarization rotation (2021)
  • Author(s): Namikawa Toshiya
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 506 Issue: 1 Pages: 1250-1257
  • DOI: 10.1093/mnras/stab1796
  • Peer Reviewed
• [Journal Article] Minimum variance estimation of statistical anisotropy via galaxy survey (2021)
  • Author(s): Shiraishi Maresuke、Okumura Teppei、Akitsu Kazuyuki
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2021 Issue: 03 Pages: 039-039
  • DOI: 10.1088/1475-7516/2021/03/039
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Cross-correlations as a diagnostic tool for primordial gravitational waves (2021)
  • Author(s): Malhotra Ameek、Dimastrogiovanni Ema、Fasiello Matteo、Shiraishi Maresuke
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2021 Issue: 03 Pages: 088-088
  • DOI: 10.1088/1475-7516/2021/03/088
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Wide-angle effects on galaxy ellipticity correlations (2021)
  • Author(s): Shiraishi Maresuke、Taruya Atsushi、Okumura Teppei、Akitsu Kazuyuki
  • Journal Title: Monthly Notices of the Royal Astronomical Society: Letters Volume: 503 Issue: 1 Pages: L6-L10
  • DOI: 10.1093/mnrasl/slab009
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Alcock-Paczynski effects on wide-angle galaxy statistics (2021)
  • Author(s): Shiraishi Maresuke、Akitsu Kazuyuki、Okumura Teppei
  • Journal Title: Physical Review D Volume: 103 Issue: 12 Pages: 123534-123534
  • DOI: 10.1103/physrevd.103.123534
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Improved sensitivity of interferometric gravitational-wave detectors to ultralight vector dark matter from the finite light-traveling time (2021)
  • Author(s): Soichiro Morisaki, Tomohiro Fujita, Yuta Michimura, Hiromasa Nakatsuka, Ippei Obata
  • Journal Title: Physical Review D Volume: 103 Issue: 5
  • DOI: 10.1103/physrevd.103.l051702
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Statistically-anisotropic tensor bispectrum from inflation (2021)
  • Author(s): Hiramatsu Takashi、Murai Kai、Obata Ippei、Yokoyama Shuichiro
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2021 Issue: 03 Pages: 047-047
  • DOI: 10.1088/1475-7516/2021/03/047
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] New Extraction of the Cosmic Birefringence from the Planck 2018 Polarization Data (2020)
  • Author(s): Minami Yuto、Komatsu Eiichiro
  • Journal Title: Physical Review Letters Volume: 125 Issue: 22 Pages: 00-00
  • DOI: 10.1103/physrevlett.125.221301
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Parity violation search using non-Gaussian observables (2023)
  • Author(s): 白石希典
  • Organizer: Domestic Molecule-type Workshop "Non-linear Nature of Cosmological Perturbations and Its Observational Consequences"
  • Int'l Joint Research / Invited
• [Presentation] Probing axions with the measurements of photon's birefringence (2023)
  • Author(s): 小幡一平
  • Organizer: Kagoshima Workshop on Particles, Fields and Strings 2023
  • Invited
• [Presentation] Parity-odd trispectrum from axion inflation (2023)
  • Author(s): 小幡一平
  • Organizer: Domestic Molecule-type Workshop "Non-linear Nature of Cosmological Perturbations and Its Observational Consequences"
  • Int'l Joint Research / Invited
• [Presentation] 宇宙複屈折に対する弱重力レンズ補正 (2023)
  • Author(s): 直川史寛
  • Organizer: 日本天文学会
• [Presentation] 宇宙複屈折に対する弱重力レンズ効果 (2023)
  • Author(s): 直川史寛
  • Organizer: 日本物理学会
• [Presentation] Weak lensing and cosmic birefringence (2023)
  • Author(s): 直川史寛
  • Organizer: Very Light Dark Matter 2023
  • Int'l Joint Research
• [Presentation] Cosmic birefringence tomography with polarized Sunyaev-Zel’dovich effect (2023)
  • Author(s): 並河俊弥
  • Organizer: Very Light Dark Matter 2023
  • Int'l Joint Research
• [Presentation] Measuring anisotropies of linear polarization rotation as a probe of primordial magnetic fields (2022)
  • Author(s): 並河俊弥
  • Organizer: JGRG online workshop
  • Int'l Joint Research
• [Presentation] A quick overview of delensing for large-scale B-modes (2022)
  • Author(s): 並河俊弥
  • Organizer: Workshop on Weak Gravitational Lensing
  • Int'l Joint Research / Invited
• [Presentation] Cosmic Birefringence: A New Probe of Dark Matter and Dark Energy (2022)
  • Author(s): 小松英一郎
  • Organizer: ICASU Inaugural Conference
  • Int'l Joint Research / Invited
• [Presentation] Cosmological signatures and constraints on primordial parity violation (2022)
  • Author(s): 白石希典
  • Organizer: 2022 Summer NRF-JSPS Workshop in particle physics, cosmology, and gravitation
  • Int'l Joint Research / Invited
• [Presentation] Isotropic cosmic birefringence from early dark energy (2022)
  • Author(s): 村井開
  • Organizer: 第11回観測的宇宙論ワークショップ
• [Presentation] Implications of the cosmic birefringence measurement for the axion dark matter search (2022)
  • Author(s): 小幡一平
  • Organizer: 17th Patras Workshop on Axions, WIMPs and WISPs
  • Int'l Joint Research
• [Presentation] Probing axions with the measurements of photon's birefringence (2022)
  • Author(s): 小幡一平
  • Organizer: The 7th IBS-ICTP-MultiDark Workshop
  • Int'l Joint Research / Invited
• [Presentation] Gravitationally Lensed Cosmic Birefringence ~for the precise prediction~ (2022)
  • Author(s): 直川史寛
  • Organizer: JGRG31
  • Int'l Joint Research
• [Presentation] CMB B-mode delensing for upcoming and future CMB experiments (2022)
  • Author(s): 並河俊弥
  • Organizer: 第11回観測的宇宙論ワークショップ
• [Presentation] A quick overview of the recent progress in measuring gravitational lensing of CMB (2022)
  • Author(s): 並河俊弥
  • Organizer: 10th Core-to-Core CMB Meeting
  • Invited
• [Presentation] 超軽量axionがCMB偏光モードに作る宇宙複屈折効果 (2022)
  • Author(s): 並河俊弥
  • Organizer: 日本天文学会年春季年会
• [Presentation] Cosmic Birefringence (2022)
  • Author(s): 小松英一郎
  • Organizer: Gravity - The Next Generation
  • Int'l Joint Research / Invited
• [Presentation] 超軽量AxionがCMB偏光モードに作る宇宙の複屈折の数値的研究 (2022)
  • Author(s): 中塚洋佑
  • Organizer: 日本物理学会
• [Presentation] Implications of the cosmic birefringence measurement for the axion dark matter search (2022)
  • Author(s): 小幡一平
  • Organizer: Recontres de Moriond
  • Int'l Joint Research
• [Presentation] Implications of the Cosmic Birefringence Measurement for the Axion Dark Matter Search (2022)
  • Author(s): 小幡一平
  • Organizer: 日本物理学会
• [Presentation] On the recent progress of axion cosmology (2022)
  • Author(s): 小幡一平
  • Organizer: 次世代CMB観測と宇宙論
  • Invited
• [Presentation] The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) (2021)
  • Author(s): 小松英一郎
  • Organizer: Radio2021 Symposium
  • Int'l Joint Research / Invited
• [Presentation] Measuring the B-mode bispectrum from BICEP/Keck Array (2021)
  • Author(s): 並河俊弥
  • Organizer: CMB-S4 Workshop
  • Int'l Joint Research / Invited
• [Presentation] Constraining reionization with the CMB optical depth fluctuation - Compton-y cross-correlation (2021)
  • Author(s): 並河俊弥
  • Organizer: CMB-S4 Workshop
  • Int'l Joint Research / Invited
• [Presentation] On the recent progress of axion cosmology (2021)
  • Author(s): 小幡一平
  • Organizer: 第10回観測的宇宙論ワークショップ
  • Invited
• [Presentation] Cosmic birerfringence measurement and its implications for the axion search (2021)
  • Author(s): 小幡一平
  • Organizer: JGRG30 online workshop
  • Int'l Joint Research
• [Presentation] Prime Focus Spectrograph: Cosmology Program (2021)
  • Author(s): 小松英一郎
  • Organizer: The 237th American Astronomical Society Meeting
  • Int'l Joint Research
• [Presentation] Delensing for Simons Observatory: New Methods to Improve Constraints on Inflation (2021)
  • Author(s): 並河俊弥
  • Organizer: The 237th American Astronomical Society Meeting
  • Int'l Joint Research
• [Presentation] Hunting for Parity-violating Physics in Polarisation of the Cosmic Microwave Background (2020)
  • Author(s): 小松英一郎
  • Organizer: NCTS Annual Theory Meeting 2020
  • Int'l Joint Research / Invited
• [Presentation] 光共振器を用いたアクシオン暗黒物質探査 (2020)
  • Author(s): 小幡一平
  • Organizer: 第５回ドイツ物理学・応用物理学セミナー
• [Presentation] Statistically-Anisotropic Tensor Bispectrum from Inflation (2020)
  • Author(s): 小幡一平
  • Organizer: JGRG online workshop
  • Int'l Joint Research
• [Remarks] New analysis strengthens the hint of new physics
  • URL: https://www.mpa-garching.mpg.de/1055454/hl202206
• [Remarks] 宇宙マイクロ波背景放射の偏光に「パリティ対称性」を破る新しい物理の兆候を観測
  • URL: https://www.ipmu.jp/ja/20201124-CosmicBirefringence
• [Remarks] A hint of new physics in polarized radiation
  • URL: https://www.mpa-garching.mpg.de/896049/news20201123
• [Funded Workshop] Very Light Dark Matter 2023 (2023)
• [Funded Workshop] Axion Day (2022)
• [Funded Workshop] Very Light Dark Matter 2021 (2021)