Why concave rather than convex inflaton potential?

Journal Article · 25 October 2018 · European Physical Journal. C, Particles and Fields

DOI: https://doi.org/10.1140/epjc/s10052-018-6357-0 · OSTI ID:1490621

Chen, Pisin ^[1]; Yeom, Dong-han  ^[2]

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1. National Taiwan University, Taipei (Taiwan); SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., CA (United States)
2. Asia Pacific Center for Theoretical Physics, Pohang (Korea); POSTECH, Pohang (Korea)

The Planck data on cosmic microwave background indicates that the Starobinsky-type model with concave inflation potential is favored over the convex-type chaotic inflation. Is there any reason for that? Here we argue that if our universe began with a Euclidean wormhole, then the Starobinsky-type inflation is probabilistically favored. It is known that for a more generic choice of parameters than that originally assumed by Hartle and Hawking, the Hartle–Hawking wave function is dominated by Euclidean wormholes, which can be interpreted as the creation of two classical universes from nothing. We show that only one end of the wormhole can be classicalized for a convex potential, while both ends can be classicalized for a concave potential. The latter is therefore more probable.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1490621
• Journal Information: European Physical Journal. C, Particles and Fields, Journal Name: European Physical Journal. C, Particles and Fields Journal Issue: 10 Vol. 78; ISSN 1434-6044
• Publisher: SpringerCopyright Statement
• Country of Publication: United States
• Language: English