2003/08/31 by Shinji Tsujikawa, Roy Maartens, Robert Brandenberger · 4 citations
Mathematics · Physics and Astronomy · #Anisotropy #Astrophysics #Black Holes and Theoretical Physics #CMB cold spot #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Inflation (cosmology) #Mathematics #Particle physics theoretical and experimental studies #Physics #Quantum mechanics #Spectral density #Spectral index #Spectral line #Statistics #String theory #Theoretical physics #astro-ph #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1016/j.physletb.2003.09.022
published as Phys.Lett.B574:141-148,2003 · Revised to clarify discussion of primordial power spectrum; to appear Phys Lett B
arxiv created 2003/09/08 · openalex publication_date 2003/10/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Non-commutative inflation is a modification of standard general relativity inflation which takes into account some effects of the space-time uncertainty principle motivated by ideas from string theory. The corrections to the primordial power spectrum which arise in a model of power-law inflation lead to a suppression of power on large scales, and produce a spectral index that is blue on large scales and red on small scales. This suppression and running of the spectral index are not imposed ad hoc, but arise from an early-Universe stringy phenomenology. We show that it can account for some loss of power on the largest scales that may be indicated by recent WMAP data. Cosmic microwave background anisotropies carry a signature of these very early Universe corrections, and can be used to place constraints on the parameters appearing in the non-commutative model. Applying a likelihood analysis to the WMAP data, we find the best-fit value for the critical wavenumber k_* (which involves the string scale) and for the exponent p (which determines the power-law inflationary expansion). The best-fit value corresponds to a string length of Ls ∼ 10-28 cm.