TY - JOUR

T1 - Non-commutative inflation and the CMB

AU - Tsujikawa, Shinji

AU - Maartens, Roy

AU - Brandenberger, Robert

N1 - Funding Information:
We are indebted to Antony Lewis for crucial advice and support in implementing and interpreting the likelihood analysis. S.T. is grateful to Bruce Bassett, Rob Crittenden and David Parkinson for useful discussions. R.B. thanks George Efstathiou for important advice. We also wish to acknowledge discussions with Stephon Alexander at the beginning of this project. S.T. acknowledges financial support from JSPS (No. 04942). R.M. is supported by PPARC. R.B. is supported in part by the US Department of Energy under Contract DE-FG02-91ER40688, TASK A.

PY - 2003/11/13

Y1 - 2003/11/13

N2 - 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 a 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.

AB - 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 a 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.

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U2 - 10.1016/j.physletb.2003.09.022

DO - 10.1016/j.physletb.2003.09.022

M3 - Article

AN - SCOPUS:0242300769

SN - 0370-2693

VL - 574

SP - 141

EP - 148

JO - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

JF - Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

IS - 3-4

ER -