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We investigate a string-inspired scenario associated with a rolling massive scalar field on D-branes and discuss its cosmological implications. Unlike the case of the tachyon field, it is possible to obtain the required level of the amplitude of density perturbations by considering D-branes in a warped metric. We study the spectra of scalar and tensor perturbations generated during the rolling scalar inflation and show that our scenario satisfies the observational constraints coming from the Cosmic Microwave Background anisotropies and other observational data. We also show an interesting possibility to explain dark energy at late times using the rolling scalar, provided that a warped factor $\beta$ is sufficiently small to produce the present value of the cosmological constant.
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