Cosmology based on quantum gravity theories

2016 Fiscal Year Annual Research Report

• Project/Area Number: 24540256
• Research Institution: Kyoto University
• Principal Investigator: 向山 信治 京都大学, 基礎物理学研究所, 教授 (40396809)
• Project Period (FY): 2012-04-01 – 2017-03-31
• Keywords: 宇宙論 / 初期宇宙 / 量子重力

Outline of Annual Research Achievements

宇宙では、様々なスケールの物理現象が互いに影響を及ぼしながら絶えず起こっている。その中でも、最も壮大なスケールの物理を対象とするのが宇宙論であり、最も基本的な最小スケールの物理が素粒子物理そして量子重力であると言えよう。重要なことは、この両極端の物理は繋がっている、繋がらなければならない、ということである(Cosmic Uroboros)。生まれたばかりの宇宙は超高エネルギーの極限的状態にあるため、ミクロの物理が本質的になるからである。本研究の目的は、量子重力理論に基づいて、宇宙のより深い理解を得ることである。初期宇宙の研究は、量子重力理論を含む、超高エネルギー物理に有益な知見をもたらすと期待される。具体的には、主に(i)量子重力理論に基づく宇宙論、(ii)非線形massive gravity理論に基づく宇宙論、(iii)その他、についての研究をおこなった。(i)においては、宇宙揺らぎを生成するカーバトン場と計量のdisformal変換について考察し、超弦理論におけるDブレーンインフレーションに適用した。その結果、カーバトン場が余剰次元の自由度なのか、あるいはブレーン上の自由度なのかによって、観測量に顕著な違いが生じくことがあることを指摘した。(ii)においては、bigravity理論においてmassive gravitonがダークマターになる可能性を考察した。(iii)においては、宇宙磁場を生成する新しいシナリオの提唱や、Generalized Proca fieldによるダークエネルギー模型・インフレーション模型の提唱をした。

Research Products

• [Int'l Joint Research] Institut Astrophysique de Paris(France)
  • Country Name: France
  • Counterpart Institution: Institut Astrophysique de Paris
• [Int'l Joint Research] Nottingham University(英国)
  • Country Name: UNITED KINGDOM
  • Counterpart Institution: Nottingham University
• [Journal Article] Graviton mass might reduce tension between early and late time cosmological data (2017)
  • Author(s): Antonio De Felice, Shinji Mukohyama
  • Journal Title: Physical Review Letters Volume: 118 Pages: 091104-1～5
  • DOI: http://dx.doi.org/10.1103/PhysRevLett.118.091104
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Where does curvaton reside? Differences between bulk and brane frames? (2017)
  • Author(s): Francois Larrouturou, Shinji Mukohyama, Ryo Namba, Yota Watanabe
  • Journal Title: Physical Review D Volume: 95 Pages: 063509-1～12
  • DOI: http://dx.doi.org/10.1103/PhysRevD.95.063509
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Stable solutions of inflation driven by vector fields (2017)
  • Author(s): Razieh Emami, Shinji Mukohyama, Ryo Namba, Ying-li Zhang
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 1703 Pages: 058-0～30
  • DOI: http://dx.doi.org/10.1088/1475-7516/2017/03/058
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] On p-form theories with gauge invariant second order field equations (2016)
  • Author(s): Cedric Deffayet, Shinji Mukohyama, Vishagan Sivanesan
  • Journal Title: Physical Review D Volume: 93 Pages: 085027-1～25
  • DOI: http://dx.doi.org/10.1103/PhysRevD.93.085027
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Ghost inflation and de Sitter entropy (2016)
  • Author(s): Sadra Jazayeri, Shinji Mukohyama, Rio Saitou, Yota Watanabe
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 1608 Pages: 002-0～17
  • DOI: http://dx.doi.org/10.1088/1475-7516/2016/08/002
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] New Quasidilaton theory in Partially Constrained Vielbein Formalism (2016)
  • Author(s): Antonio De Felice, A.Emir Gumrukcuoglu, Lavinia Heisenberg, Shinji Mukohyama, Norihiro Tanahashi
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 1605 Pages: 061-0～17
  • DOI: http://dx.doi.org/10.1088/1475-7516/2016/05/061
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Cosmology in generalized Proca theories (2016)
  • Author(s): Antonio De Felice, Lavinia Heisenberg, Ryotaro Kase, Shinji Mukohyama, Shinji Tsujikawa, Ying-li Zhang
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 1606 Pages: 048-0～32
  • DOI: http://dx.doi.org/10.1088/1475-7516/2016/06/048
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Massive gravitons as dark matter and gravitational waves (2016)
  • Author(s): Katsuki Aoki, Shinji Mukohyama
  • Journal Title: Physical Review D Volume: 94 Pages: 024001-1～11
  • DOI: http://dx.doi.org/10.1103/PhysRevD.94.024001
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Effective gravitational couplings for cosmological perturbations in generalized Proca theories (2016)
  • Author(s): Antonio De Felice, Lavinia Heisenberg, Ryotaro Kase, Shinji Mukohyama, Shinji Tsujikawa, Ying-li Zhang
  • Journal Title: Physical Review D Volume: 94 Pages: 044024-1～20
  • DOI: http://dx.doi.org/10.1103/PhysRevD.94.044024
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Is the DBI scalar field as fragile as other k-essence fields? (2016)
  • Author(s): Shinji Mukohyama, Ryo Namba, Yota Watanabe
  • Journal Title: Physical Review D Volume: 94 Pages: 023514-1～10
  • DOI: http://dx.doi.org/10.1103/PhysRevD.94.023514
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Low energy ghosts and the Jeans’ instability (2016)
  • Author(s): A.Emir Gumrukcuoglu, Shinji Mukohyama, Thomas P. Sotiriou
  • Journal Title: Physical Review D Volume: 94 Pages: 064001-1～6
  • DOI: http://dx.doi.org/10.1103/PhysRevD.94.064001
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Stealth magnetic field in de Sitter spacetime (2016)
  • Author(s): Shinji Mukohyama
  • Journal Title: Physical Review D Volume: 94 Pages: 121302-1～6
  • DOI: http://dx.doi.org/10.1103/PhysRevD.94.121302
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Role of matter in extended quasidilaton massive gravity (2016)
  • Author(s): A. Emir Gumrukcuoglu, Kazuya Koyama, Shinji Mukohyama
  • Journal Title: Physical Review D Volume: 94 Pages: 123510-1～14
  • DOI: http://dx.doi.org/10.1103/PhysRevD.94.123510
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Gravitational scalar-tensor theory (2016)
  • Author(s): Atsushi Naruko, Daisuke Yoshida, Shinji Mukohyama
  • Journal Title: Classical and Quantum Gravity Volume: 33 Pages: 09LT01-1～8
  • DOI: http://dx.doi.org/10.1088/0264-9381/33/9/09LT01
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Phenomenology in minimal theory of massive gravity (2016)
  • Author(s): Antonio De Felice, Shinji Mukohyama
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 1604 Pages: 028-0～26
  • DOI: http://dx.doi.org/10.1088/1475-7516/2016/04/028
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Presentation] Ghost Condensation and Horizon Entropy (2016)
  • Author(s): Shinji Mukohyama
  • Organizer: Modern aspects of gravity and cosmology
  • Place of Presentation: Orsay, France
  • Year and Date: 2016-11-04 – 2016-11-04
  • Int'l Joint Research / Invited
• [Presentation] Is DBI as fragile as other k-essence fields? (2016)
  • Author(s): Shinji Mukohyama
  • Organizer: IF-YITP GR+HEP+Cosmo International Symposium VI
  • Place of Presentation: Naresuan University, Thailand
  • Year and Date: 2016-08-04 – 2016-08-04
  • Int'l Joint Research / Invited
• [Presentation] Ghost Condensation and Horizon Entropy (2016)
  • Author(s): Shinji Mukohyama
  • Organizer: IF-YITP GR+HEP+Cosmo International Symposium VI
  • Place of Presentation: Naresuan University, Thailand
  • Year and Date: 2016-08-04 – 2016-08-04
  • Int'l Joint Research / Invited
• [Presentation] Minimal Theory of Massive gravity (2016)
  • Author(s): Shinji Mukohyama
  • Organizer: Hot topics in Modern Cosmology
  • Place of Presentation: Cargese, France
  • Year and Date: 2016-05-10 – 2016-05-10
  • Int'l Joint Research / Invited
• [Presentation] Ghost Condensation and Horizon Entropy (2016)
  • Author(s): Shinji Mukohyama
  • Organizer: Hot topics in Modern Cosmology
  • Place of Presentation: Cargese, France
  • Year and Date: 2016-05-09 – 2016-05-09
  • Int'l Joint Research / Invited
• [Presentation] Status of Ghost Condensation (2016)
  • Author(s): Shinji Mukohyama
  • Organizer: 3rd Korea-Japan Workshop on Dark Energy
  • Place of Presentation: Korea Astronomy and Space Science Institute, Daejeon, South Korea
  • Year and Date: 2016-04-04 – 2016-04-04
  • Int'l Joint Research / Invited