2009/07/31 by Ido Ben-Dayan, Ram Brustein
Earth and Planetary Sciences · Physics and Astronomy · #Anisotropy #Astrophysics #Black Holes and Theoretical Physics #Cosmic background radiation #Cosmic microwave background #Cosmological perturbation theory #Cosmology #Cosmology and Gravitation Theories #Geophysics and Gravity Measurements #Gravitational wave #Inflation (cosmology) #Observable #Physics #Planck #Quantum mechanics #Spectral density #Spectral index #Spectral line #Statistical physics #Statistics #Theoretical physics #astro-ph.CO #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2010/09/007
published as JCAP 1009:007,2010 · 13 pages, 3 figures, added numerical analysis and discussion on the properties of the spectra. Version to be published in JCAP
arxiv created 2010/08/24 · openalex publication_date 2010/09/09 · arxiv updated 2014/11/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We construct a class of single small field models of inflation that can predict, contrary to popular wisdom, an observable gravitational wave signal in the cosmic microwave background anisotropies. The spectral index, its running, the tensor to scalar ratio and the number of e-folds can cover all the parameter space currently allowed by cosmological observations. A unique feature of models in this class is their ability to predict a negative spectral index running in accordance with recent cosmic microwave background observations. We discuss the new class of models from an effective field theory perspective and show that if the dimensionless trilinear coupling is small, as required for consistency, then the observed spectral index running implies a high scale of inflation and hence an observable gravitational wave signal. All the models share a distinct prediction of higher power at smaller scales, making them easy targets for detection.