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We present a unified theory of inflation, neutrino mass, baryogenesis, and dark matter where global lepton number symmetry and its breaking play a crucial role. The basic idea is to use a lepton number carrying a complex scalar field as the inflaton as well as the field that implements Affleck-Dine (AD) leptogenesis. Dark matter is the massive Majoron which is a pseudo-Goldstone boson, resulting from the spontaneous breaking of lepton number symmetry supplemented by explicit lepton number violation needed to implement AD leptogenesis. The magnitude of the resulting nB/s in the model is related to the mass of the pseudo-Goldstone dark matter, connecting two apparently disconnected cosmological observations. An inverse seesaw mechanism with lepton number breaking at low scale is crucial to prevent washout of the lepton asymmetry during the universe’s evolution. The model seems to provide an economical solution to several puzzles of the standard model of particle physics and cosmology in one stroke.
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TwInflation
A bstract The general structure of Hybrid Inflation remains a very well-motivated mechanism for lower-scale cosmic inflation in the face of improving constraints on the tensor-to-scalar ratio. However, as originally modeled, the “waterfall” field in this mechanism gives rise to a hierarchy problem ( η− problem) for the inflaton after demanding standard effective field theory (EFT) control. We modify the hybrid mechanism and incorporate a discrete “twin” symmetry, thereby yielding a viable, natural and EFT-controlled model of non-supersymmetric low-scale inflation, “Twinflation”. Analogously to Twin Higgs models, the discrete exchange-symmetry with a “twin” sector reduces quadratic sensitivity in the inflationary potential to ultra-violet physics, at the root of the hierarchy problem. The observed phase of inflation takes place on a hilltop-like potential but without fine-tuning of the initial inflaton position in field-space. We also show that all parameters of the model can take natural values, below any associated EFT-cutoff mass scales and field values, thus ensuring straightforward theoretical control. We discuss the basic phenomenological considerations and constraints, as well as possible future directions.
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- Award ID(s):
- 1914731
- PAR ID:
- 10280972
- Date Published:
- Journal Name:
- Journal of High Energy Physics
- Volume:
- 2021
- Issue:
- 7
- ISSN:
- 1029-8479
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1007/JHEP07(2021)147
