Search Results 1-20 of 140

  • Evolution of dissipative and nondissipative universes in holographic cosmological models with a power-law term

    Komatsu Nobuyoshi , 小松 信義

    … The first type is a "Λ(t) model" similar to a time-varying Λ(t) cosmology for the nondissipative universe. … The second type is a "BV model" similar to a bulk viscous cosmology for the dissipative universe. … To systematically examine the two different universes, a power-law term proportional to Hα is applied to the Λ(t) and BV (bulk-viscous-cosmology-like) models, assuming a flat Friedmann-Robertson-Walker model for the late universe. …

    Physical Review D 103(2), 023534, 2021-01-25

    IR  DOI 

  • Weak-lensing Mass Calibration of ACTPol Sunyaev–Zel'dovich Clusters with the Hyper Suprime-Cam Survey

    Miyatake Hironao , Battaglia Nicholas , Hilton Matt , Medezinski Elinor , Nishizawa Atsushi J. , More Surhud , Aiola Simone , Bahcall Neta , Bond J. Richard , Calabrese Erminia , Choi Steve K. , Devlin Mark J. , Dunkley Joanna , Dunner Rolando , Fuzia Brittany , Gallardo Patricio , Gralla Megan , Hasselfield Matthew , Halpern Mark , Hikage Chiaki , Hill J. Colin , Hincks Adam D. , Hložek Renée , Huffenberger Kevin , Hughes John P. , Koopman Brian , Kosowsky Arthur , Louis Thibaut , Madhavacheril Mathew S. , McMahon Jeff , Mandelbaum Rachel , Marriage Tobias A. , Maurin Loïc , Miyazaki Satoshi , Moodley Kavilan , Murata Ryoma , Naess Sigurd , Newburgh Laura , Niemack Michael D. , Nishimichi Takahiro , Okabe Nobuhiro , Oguri Masamune , Osato Ken , Page Lyman , Partridge Bruce , Robertson Naomi , Sehgal Neelima , Sherwin Blake , Shirasaki Masato , Sievers Jonathan , Sifón Cristóbal , Simon Sara , Spergel David N. , Staggs Suzanne T. , Stein George , Takada Masahiro , Trac Hy , Umetsu Keiichi , Engelen Alex van , Wollack Edward J.

    … We present weak-lensing measurements using the first-year data from the Hyper Suprime-Cam Strategic Survey Program on the Subaru telescope for eight galaxy clusters selected through their thermal Sunyaev–Zel'dovich (SZ) signal measured at 148 GHz with the Atacama Cosmology Telescope Polarimeter experiment. …

    The Astrophysical Journal 875(1), 63, 2019-04


  • Towards Understanding the Inflationary Universe――Perspectives from Current and Future Cosmological Observations  [in Japanese]

    Takahashi Tomo

    <p>宇宙誕生の直後,宇宙はインフレーションと呼ばれる急激な加速膨張の時期を経験したと考えられている.このインフレーションは,元来標準ビッグバン宇宙論における諸問題(地平線問題,平坦性問題など)を解決するために提案されたが,しかしそれだけでなく,宇宙の大規模構造や宇宙背景放射の揺らぎなどの宇宙の構造の起源(原始密度揺らぎ)を与えることができる.インフレーションはほぼスケール不変で,ほぼ …

    Butsuri 74(7), 463-471, 2019


  • Formation of the first generation of stars and blackholes in the Universe

    YOSHIDA Naoki

    … The standard theoretical model based on an array of recent observations accurately predicts the physical conditions in the early Universe, and powerful super-computers allow us to simulate in detail the formation and evolution of cosmic structure to the present epoch. … Finally, we discuss prospects for future observations of the first stars, galaxies and blackholes.</p> …

    Proceedings of the Japan Academy, Series B 95(1), 17-28, 2019


  • AKARI's Legacy to SPICA

    山村 一誠 , 「あかり」チーム , Yamamura Issei , AKARI team

    形態: カラー図版あり資料番号: AA1730027094レポート番号: JAXA-SP-17-010E

    宇宙航空研究開発機構特別資料 = JAXA Special Publication: Proceedings of the SPICA Science Conference from Exoplanets to Distant Galaxies: SPICA's New Window on the Cool Universe (JAXA-SP-17-010E), 423-426, 2018-03-09


  • From AKARI to SPICA: a New Window to Understand Links between Cosmology and Galaxy Evolution

    Pollo Agnieszka , 竹内 努 , Malek Katarzyna , Solarz Aleksandra , Pepiak Agata , 松原 英雄 , AKARI team , Pollo Agnieszka , Takeuchi Tsutomu T. , Malek Katarzyna , Solarz Aleksandra , Pepiak Agata , Matsuhara Hideo , AKARI team

    形態: カラー図版あり資料番号: AA1730027014レポート番号: JAXA-SP-17-010E

    宇宙航空研究開発機構特別資料 = JAXA Special Publication: Proceedings of the SPICA Science Conference from Exoplanets to Distant Galaxies: SPICA's New Window on the Cool Universe (JAXA-SP-17-010E), 71-74, 2018-03-09


  • Starforming Galaxies Detected in Blind Spectroscopic Surveys with SPICA/SAFARI: Model Predictions

    Negrello Mattia , Bonato Matteo , Cai Zhen-Yi , DeZotti Gianfranco

    形態: カラー図版あり資料番号: AA1730027011レポート番号: JAXA-SP-17-010E

    宇宙航空研究開発機構特別資料 = JAXA Special Publication: Proceedings of the SPICA Science Conference from Exoplanets to Distant Galaxies: SPICA's New Window on the Cool Universe (JAXA-SP-17-010E), 59-62, 2018-03-09


  • Stable cosmology in chameleon bigravity

    De Felice Antonio , Mukohyama Shinji , Oliosi Michele , Watanabe Yota

    … This paper extends the previous work by presenting a stable example of cosmology in the chameleon bigravity model. … We also argue that our model satisfies all known constraints due to gravitational wave observations so far and thus can be considered as a unique testing ground of gravitational wave phenomenologies in bimetric theories of gravity. …

    Physical Review D 97(2), 2018-01-15


  • Galileo Galilei's Astronomical Observations and New Cosmology  [in Japanese]

    伊藤 和行

    哲学研究 (601), 29-55, 2017-06

  • Constraint on ghost-free bigravity from gravitational Cherenkov radiation

    Kimura Rampei , Tanaka Takahiro , Yamamoto Kazuhiro , Yamashita Yasuho

    … We found that the gravitational Cherenkov radiation emitted even from an ultrahigh energy cosmic ray is sufficiently suppressed for the graviton's effective mass less than 100 eV, and the bigravity model with dark matter coupled to the hidden metric is therefore consistent with observations of high energy cosmic rays. …

    Physical Review D - Particles, Fields, Gravitation, and Cosmology 94(6), 2016-09-21


  • Cosmic microwave background radiation temperature in a dissipative universe

    Komatsu Nobuyoshi , Kimura Shigeo

    … The T-z relation for μ=0 is linear for standard cosmology and is consistent with observations. … When the background evolution of the Universe agrees with a fine-tuned pure lambda cold dark matter model, the T-z relation for low μ matches observations, whereas the T-z relation for high μ does not. … The weakly dissipative model should be further constrained by recent observations. …

    Physical Review D - Particles, Fields, Gravitation and Cosmology 92(4), 043507, 2015-08-06



    Umetsu Keiichi , Sereno Mauro , Medezinski Elinor , Nonino Mario , Mroczkowski Tony , Diego Jose M. , Ettori Stefano , Okabe Nobuhiro , Broadhurst Tom , Lemze Doron

    … We perform a three-dimensional multi-probe analysis of the rich galaxy cluster A1689, one of the most powerful known lenses on the sky, by combining improved weak-lensing data from new wide-field BVRCi'z' Subaru/ Suprime-Cam observations with strong-lensing, X-ray, and Sunyaev–Zel'dovich effect (SZE) data sets. … Support for the SZA observations presented in this work was provided by NSF through award AST-0838187 and PHY-0114422 at the University of Chicago. …

    The Astrophysical Journal 806(2), 207, 2015-06-20


  • The Initial State of a Primordial Anisotropic Stage of Inflation

    Blanco-Pillado Jose J. , Minamitsuji Masato

    … On the other hand, the spectrum of the universe with a dS2 × T2 parent vacuum presents an enhancement in power at large scales not consistent with observations. …

    Journal of Cosmology and Astroparticle Physics (2015), 2015-06-12


  • Entropic cosmology in a dissipative universe

    Komatsu Nobuyoshi , Kimura Shigeo

    … With increasing dissipation rate μ, the calculated growth rate for the clustering gradually deviates from observations, especially at low redshifts. …

    Physical Review D - Particles, Fields, Gravitation and Cosmology 90(12), 123516, 2014-12-12


  • Galaxy luminosity function and its cosmological evolution: testing a new feedback model depending on galaxy-scale dust opacity

    Makiya Ryu , Totani Tomonori , Kobayashi M. A R , Nagashima Masahiro , Takeuchi Tomotake

    … We present a new version of a semi-analytic model of cosmological galaxy formation, incorporating a star formation law with a feedback depending on the galaxy-scale mean dust opacity and metallicity, motivated by recent observations of star formation in nearby galaxies and theoretical considerations. … Though some of the previous models also succeeded in reproducing this, they assumed a star formation law depending on the galaxy-scale dynamical time, which is not supported by observations. …

    Monthly Notices of the Royal Astronomical Society 441(1), 63-72, 2014-05


  • Bias-hardened CMB lensing with polarization

    Namikawa T. , Takahashi R.

    Polarization data will soon provide the best method for measuring the CMB lensing potential, although these data are potentially sensitive to several instrumental effects, including beam asymmetry, po …

    Monthly Notices of the Royal Astronomical Society 438(2), 1507-1517, 2014-01-28


  • Kiso Supernova Survey (KISS) : Survey strategy

    MOROKUMA Tomoki , TOMINAGA Nozomu , TANAKA Masaomi [他]

    Publications of the Astronomical Society of Japan 66(6), 114-1-16, 2014

  • A study of selection methods for Hα-emitting galaxies at z~1.3 for the Subaru/FMOS galaxy redshift survey for cosmology (FastSound)

    TONEGAWA Motonari , TOTANI Tomonori , AKIYAMA Masayuki [他]

    Publications of the Astronomical Society of Japan 66(2), 43-1-13, 2014

  • Application of Buginese-Makassarese culture in Makassar City, Indonesia:A Reference in the Coastal City Planning

    Akil Arifuddin , Yudono Ananto , Latief Ihsan , Radja Abdul Mufti

    … The method which is used is a triangle analysis, a method which analyzes the literature, in-depth interviews with community leaders, and observations of the socio-cultural and physical morphology in the research area. … From this study, it was found that the Buginese-Makassarese community have local knowledge based on culture, cosmology, and philosophy which have been understood since long ago. …

    International Review for Spatial Planning and Sustainable Development 2(4), 68-80, 2014

    IR  J-STAGE 

  • A Complete Census of the X-ray Brightest Galaxy Cluster out to the Virial Radius with Suzaku(Research)  [in Japanese]

    Simionescu Aurora , Werner Norbert , Mitsuda Kazuhisa

    銀河団は,差し渡し数百万光年の空間に数十個から1,000個もの銀河が集中している宇宙最大の天体です.普通の物質(バリオン)に限ると,銀河団の主たる構成要素は実は銀河ではなく,温度数千万度の高温ガスです.銀河団中のバリオンのほとんどは,X線を発する高温ガスとして銀河と銀河の間の空間に存在します.銀河団は,X線を放射する高温ガスの海の中に個々の銀河が浮かんでいるような天体と言えるでしょう.「すざく」衛 …

    Butsuri 69(10), 707-711, 2014


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