New model of axion monodromy inflation and its cosmological implications
- CAS Key Laboratory for Researches in Galaxies and Cosmology,Department of Astronomy, University of Science and Technology of China,Chinese Academy of Sciences, Hefei, Anhui 230026 (China)
- Kavli Institute for Theoretical Physics, University of California,Santa Barbara, California 93106 (United States)
- Department of Physics, McGill University,Montréal, QC, H3A 2T8 (Canada)
We propose a new realization of axion monodromy inflation in which axion monodromy arises from torsional cycles in a type IIB compactification. A class of monomial potentials is obtained with specific values for the power index. Moreover, the inflaton mass changes profile due to the couplings between various fields after compactification. Consequently, the potential obtains a step-like profile at some critical scale. We study the cosmological implications of one concrete realization of this model. At the background level, it realizes a sufficiently long inflationary stage, which allows for the violation of the slow-roll conditions for a short period of time when the inflaton is close to the critical scale. Accordingly, the Hubble horizon is perturbed and affects the dynamics of primordial cosmological perturbations. In particular, we analyze the angular power spectrum of B-mode polarization and find a boost on very large scales. We also find that the amplitude of scalar perturbations is suppressed near the critical scale. Thus our model provides an interpretation for the low-ℓ suppression of temperature anisotropies in the CMB power spectrum. We examine these effects and confront the model to observations.
- Sponsoring Organization:
- SCOAP3, CERN, Geneva (Switzerland)
- OSTI ID:
- 22572097
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2016, Issue 06; Other Information: PUBLISHER-ID: JCAP06(2016)027; OAI: oai:repo.scoap3.org:15990; cc-by Article funded by SCOAP3. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 License. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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