Enhancement of primordial curvature perturbations in <i>R</i> <sup>3</sup> -corrected Starobinsky-Higgs inflation
Abstract We provide a systematic study of the Starobinsky-Higgs inflation model in the presence of an additional cubic term of the Ricci scalar. We investigate, in particular, the effects of the cubic term on the spectral index n s and the tensor-to-scalar ratio r . Through both analytical and numerical analyses, we show that the R 3 -corrected Starobinsky-Higgs model can achieve compatibility with cosmic microwave background observations while producing distinct observational signatures with different frequency ranges. In addition, we discuss the complementarity between different observational probes, including the scalar-induced gravitational waves and spectral distortions, offering an independent probe of the enhanced curvature perturbations. Detection prospects are also discussed.
Authors
- Ying-li Zhang (ORCID: https://orcid.org/0000-0003-0396-1408)
- Xinpeng Wang (ORCID: https://orcid.org/0000-0002-0369-6774)
- Jinsu Kim (ORCID: https://orcid.org/0000-0001-7718-6067)
- Zhongzhou Ren
Institutions
- Tongji University (CN)
- Kavli Institute for the Physics and Mathematics of the Universe (JP)
- The University of Tokyo (JP)
Publication Details
- Journal
- Journal of Cosmology and Astroparticle Physics
- Published
- 2025-09-01
- DOI
- https://doi.org/10.1088/1475-7516/2025/09/011
- Citations
- 24
- Primary Topic
- Cosmology and Gravitation Theories
- Type
- article
- Field-Weighted Citation Impact
- 27.71
Funders
- Ministry of Education, Culture, Sports, Science and Technology
- National Natural Science Foundation of China
- Japan Society for the Promotion of Science
- Fundamental Research Funds for the Central Universities