| DATE: |
2014-06-03 11:00 - 12:00 |
| PLACE: |
Kenkyu Honkan 1F meeting room 1 |
| TITLE: |
Natural inflation with effective large decay constant by hierarchical charge |
| CONTACT: |
Ryosuke Sato, rsato-AT-post.kek.jp |
| SPEAKER: |
Dr. Keisuke Harigaya (Kavli IPMU) |
| LANGUAGE: |
English |
| ABSTRACT: |
Natural inflation is a large field model, which is favored from the view point of the initial condition problem. The inflaton can be understood as a Nambu Goldstone boson associated with a spontaneous breaking of an U(1) symmetry. The inflaton potential can be understood as an explicite breaking of the U(1) symmetry to a discrete one. Since the decay constant of the inflaton must be larger than the Planck scale for a successful slow-roll inflation, it is not clear whether natural inflation model can be treated by four dimensional field theory, which has a cut off at the Planck scale. In this talk, I show that the large decay constant can be obtained from a field theory with all the scale below the Planck scale, by considering hierarchical U(1) charges. |
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