2014/06/19 by Csaba Csáki, Csaba Csaki, Nemanja Kaloper +2 · 68 citations
Earth and Planetary Sciences · Physics and Astronomy · #Black Holes and Theoretical Physics #Classical mechanics #Cosmic microwave background #Cosmology and Gravitation Theories #Geophysics and Gravity Measurements #Inflation (cosmology) #Inflaton #Mathematical physics #Physics #Planck scale #Quantum #Quantum gravity #Quantum mechanics #Scale (ratio) #Scale invariance #Symmetry breaking #Theoretical physics #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevlett.113.161302
published in Physical Review Letters 113(16), 161302 (American Physical Society) · 18 pages, 3 figures
arxiv created 2014/06/19 · openalex publication_date 2014/10/14 · arxiv updated 2014/10/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We construct a model of inflation based on a low-energy effective theory of spontaneously broken global scale invariance. This provides a shift symmetry that protects the inflaton potential from quantum corrections. Since the underlying scale invariance is noncompact, arbitrarily large inflaton field displacements are readily allowed in the low-energy effective theory. A weak breaking of scale invariance by almost marginal operators provides a nontrivial inflaton minimum, which sets and stabilizes the final low-energy value of the Planck scale. The underlying scale invariance ensures that the slow-roll approximation remains valid over large inflaton displacements, and yields a scale invariant spectrum of perturbations, as required by the cosmic microwave background observations.