%0 Journal Article
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%@nexthigherunit 8JMKD3MGPCW/3ETR8EH
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%3 inflationary.pdf
%X We study DBI inflation based upon a general model characterized by a power-law flow parameter ()  á and speed of sound cs()  â, where á and â are constants. We show that in the slow-roll limit this general model gives rise to distinct inflationary classes according to the relation between á and â and to the time evolution of the inflaton field, each one corresponding to a specific potential; in particular, we find that the well-known canonical polynomial (large- and small-field), hybrid and exponential potentials also arise in this non-canonical model. We find that these non-canonical classes have the same physical features as their canonical analogs, except for the fact that the inflaton field evolves with varying speed of sound; also, we show that a broad class of canonical and D-brane inflation models are particular cases of this general non-canonical model. Next, we compare the predictions of large-field polynomial models with the current observational data, showing that models with low speed of sound have red-tilted scalar spectrum with low tensor-to-scalar ratio, in good agreement with the observed values. These models also show a correlation between large non-gaussianity with low tensor amplitudes, which is a distinct signature of DBI inflation with large-field polynomial potentials.
%@mirrorrepository sid.inpe.br/mtc-m19@80/2009/08.21.17.02.53
%T Inflationary potentials in DBI models
%@secondarytype PRE PI
%K inflation, alternatives to inflation.
%@group DAS-CEA-INPE-MCT-BR
%@secondarykey INPE--PRE/
%@issn 1475-7516
%2 sid.inpe.br/mtc-m19@80/2009/12.09.18.30.31
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation University at Buffalo
%@affiliation University at Buffalo
%B Journal of Cosmology and Astroparticle Physics
%4 sid.inpe.br/mtc-m19@80/2009/12.09.18.30
%D 2009
%V 31
%@doi 10.1088/1475-7516/2009/09/031
%A Bessada, Dennis,
%A Kinney, William H.,
%A Tzirakis, Konstantinos,
%@area CEA