2006/10/21 by Qing-Guo Huang
Mathematics · Physics and Astronomy · #Anisotropy #Astrophysics #Black Holes and Theoretical Physics #CMB cold spot #Cosmic background radiation #Cosmic microwave background #Cosmology and Gravitation Theories #Geometry #Index (typography) #Inflation (cosmology) #Mathematical analysis #Mathematical physics #Mathematics #Noncommutative geometry #Particle physics theoretical and experimental studies #Physics #Quantum mechanics #Scalar (mathematics) #Spectral index #Spectral line #Theoretical physics #Upper and lower bounds #astro-ph
paper · pdf · doi:10.1088/1475-7516/2006/11/004
published as JCAP0611:004,2006 · 15 pages, 4 figures; references and one figure are added, version for publication in JCAP
arxiv created 2006/10/21 · openalex publication_date 2006/11/09 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Three-year data of WMAP implies not only a negative running of the spectral index with large absolute value, but also a large positive running of running of the spectral index with order of the magnitude 10-2. We calculate the running of running in usual inflation model and noncommutative inflation model. A large tensor-scalar ratio r\≥ 1.23 is needed in order to fit the WMAP data in the noncommutative inflation model, which roughly saturates the observational upper bound on it.