TY - JOUR
T1 - Density perturbations in the ekpyrotic Universe and string-inspired generalizations
AU - Tsujikawa, Shinji
N1 - Funding Information:
The author thanks Bruce Bassett, Robert Brandenberger, Cyril Cartier, Alexei Starobinsky, and Jun'ichi Yokoyama for useful discussions. He is also thankful for financial support from the JSPS (No. 04942).
PY - 2002
Y1 - 2002
N2 - We study density perturbations in several cosmological models motivated by string theory. The evolution and the spectra of curvature perturbations R are analyzed in the ekpyrotic scenario and nonsingular string cosmologies. We find that these string-inspired models generally exhibit blue spectra in contrast to standard slow-roll inflationary scenarios. We also clarify the parameter range where R is enhanced on superhorizon scales.
AB - We study density perturbations in several cosmological models motivated by string theory. The evolution and the spectra of curvature perturbations R are analyzed in the ekpyrotic scenario and nonsingular string cosmologies. We find that these string-inspired models generally exhibit blue spectra in contrast to standard slow-roll inflationary scenarios. We also clarify the parameter range where R is enhanced on superhorizon scales.
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U2 - 10.1016/S0370-2693(01)01526-X
DO - 10.1016/S0370-2693(01)01526-X
M3 - Article
AN - SCOPUS:0000025865
SN - 0370-2693
VL - 526
SP - 179
EP - 185
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 -