225 research outputs found
On the waterfall behavior in hybrid inflation
We revisit the hybrid inflation model focusing on the dynamics of the
waterfall field in an analytical way. It is shown that inflation may last long
enough during the waterfall regime for some parameter regions, confirming the
claim of Clesse. In this case the scalar spectral index becomes red, and can
fall into the best fit range of the WMAP observation.Comment: 10 pages, 9 figure
Can decaying particle explain cosmic infrared background excess?
Recently the CIBER experiment measured the diffuse cosmic infrared background
(CIB) flux and claimed an excess compared with integrated emission from
galaxies. We show that the CIB spectrum can be fitted by the additional photons
produced by the decay of a new particle. However, it also contributes too much
to the anisotropy of the CIB, which is in contradiction with the anisotropy
measurements by the CIBER and Hubble Space Telescope.Comment: 14 pages, 3 figure
Supernova Cosmology and the Fine Structure Constant
We study the dependence of the peak luminosity of Type Ia supernovae on the
fine structure constant . We find that decreasing (increasing)
enhances (reduces) the luminosity. Future experiments like SNAP could determine
the variation of to a precision of .Comment: 6 page
Quintessence Cosmology and Varying
If the reported measurements of the time variation of the fine structure
constant from observations of distant QSOs are correct, combined with the Oklo
limit they would strongly constrain the class of the quintessence potential. If
these results prove valid, future satellite experiment (STEP) should measure
the induced violation of the weak equivalence principle. Future cosmological
observations of nearby (z \siml 0.5) absorption systems would make it clear
whether the variation is significant or not.Comment: 7 page
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