Verification of the effects inspired by superstring theory on the generation of primordial perturbations during inflation

• Project/Area Number: 26887042
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Waseda University
• Principal Investigator: MIZUNO Shuntaro 早稲田大学, 高等研究所, 助教 (60386620)
• Project Period (FY): 2014-08-29 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2014: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: 宇宙物理（理論）

Outline of Final Research Achievements

In this research, I investigate the influence of D-brane and heavy fields that can be obtained out of string theory on the generation of primordial perturbations during inflation. I clarified the constraints on the primordial non-Gaussianity generated by DBI inflation and DBI galileon inflation with the observations of cosmic microwave background radiation and large scale structure. I also showed that the effect of heavy fields becomes so large that the features in primordial spectra that are generated by the resonance effect can be detected by future observation if the fields have non-canonical kinetic terms. I also pointed out interesting cosmological possibilities with a class of scalar-tensor theory of gravity that is obtained by generalizing galileon models and a gravitational derivative coupling term.

Research Products

• [Journal Article] Gravitational Baryogenesis after Anisotropic Inflation (2016)
  • Author(s): Mitsuhiro Fukushima, Shuntaro Mizuno, Kei-ichi Maeda
  • Journal Title: Physical Review D Volume: 印刷中
  • Acknowledgement Compliant
• [Journal Article] Modified gravity inside astrophysical bodies (2015)
  • Author(s): Ryo Saito, Daisuke Yamauchi, Shunttaro Mizuno, Jerome Gleyzes
  • Journal Title: Journal of Cosmology and Astroparticle Physicls Volume: Volume 2015 June Issue: 06 Pages: 1-12
  • DOI: 10.1088/1475-7516/2015/06/008
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Halo/Galaxy Bispectrum with Equilateral-type Primordial Trispectrum (2015)
  • Author(s): Shuntaro Mizuno, Shuichiro Yokoyama
  • Journal Title: Physical Review D Volume: 91, 12 Issue: 12
  • DOI: 10.1103/physrevd.91.123521
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Modified gravity inside astrophysical bodies (2015)
  • Author(s): Ryo Saito, Daisuke Yamauchi, Shuntaro Mizuno, Jérôme Gleyzes, David Langlois
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 印刷中
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Orthogonal non-Gaussianity in DBI galileon: prospect for Planck polarization and post-Planck experiments (2014)
  • Author(s): Kazuya Koyama, Guido Walter Pettinari, Shuntaro Mizuno and Christian Fidler
  • Journal Title: Classical and Quantum Gravity Volume: Volume 31 Number 12 Issue: 12 Pages: 125003-125003
  • DOI: 10.1088/0264-9381/31/12/125003
  • Peer Reviewed
• [Journal Article] Combined features in the primordial spectra induced by a sudden turn in two-field DBI inflation (2014)
  • Author(s): Shuntaro Mizuno, Ryo Saito and David Langlois
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: Volume 2014 November Issue: 11 Pages: 032-032
  • DOI: 10.1088/1475-7516/2014/11/032
  • Peer Reviewed
• [Presentation] Halo/galaxy bispectrum with equilateral-type primordial trispectrum (2015)
  • Author(s): 水野俊太郎、 横山修一郎
  • Organizer: 観測的宇宙論ワークショップ
  • Place of Presentation: 京都大学 （京都府・京都市）
  • Year and Date: 2015-11-18
• [Presentation] Halo/galaxy bispectrum with equilateral-type primordial trispectrum (2015)
  • Author(s): 水野俊太郎、 横山修一郎
  • Organizer: 日本物理学会
  • Place of Presentation: 大阪市立大学 （大阪府・大阪市）
  • Year and Date: 2015-09-25
• [Presentation] Halo/galaxy bispectrum with equilateral-type primordial trispectrum (2015)
  • Author(s): 水野俊太郎、 横山修一郎
  • Organizer: COSMO2015
  • Place of Presentation: ワルシャワ （ポーランド）
  • Year and Date: 2015-09-07
  • Int'l Joint Research
• [Presentation] Influence of equilateral-type non-Gaussianity in large scale structure (2015)
  • Author(s): 水野 俊太郎、 横山 修一郎
  • Organizer: 日本物理学会
  • Place of Presentation: 早稲田大学
  • Year and Date: 2015-03-21 – 2015-03-24
• [Presentation] Combined features in the primordial spectra induced by a sudden turn in two-field DBI inflation (2014)
  • Author(s): 水野 俊太郎, 齊藤 遼, David Langlois
  • Organizer: JGRG 24
  • Place of Presentation: Kavli-IPMU
  • Year and Date: 2014-11-10 – 2014-11-14
• [Presentation] Influence of heavy modes on perturbations in multiple field DBI inflation (2014)
  • Author(s): 水野 俊太郎, 齊藤 遼, David Langlois
  • Organizer: 日本物理学会
  • Place of Presentation: 佐賀大学
  • Year and Date: 2014-09-18 – 2014-09-21