Institute of Astrophysics and Space Sciences

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Organizational Unit

Publications

Multi-field cold and warm inflation and the de sitter swampland conjectures

Publication . Bertolami, Orfeu; Sá, Paulo

We discuss under which conditions multi-field cold and warm inflationary models with canonical kinetic energy terms are compatible with the swampland conjectures about the emergence of de Sitter solutions in string theory. We find that under quite general con-ditions the slow-roll conditions for multi-field cold inflation are at odds with the swampland conjectures for an arbitrary number of scalar fields driving inflation. However, slow-roll con-ditions can be reconciled with the swampland conjectures in the strong dissipative regime of warm inflation.

2022-09Journal article

Restricted access

Coupled quintessence inspired by warm inflation

Publication . Sá, Paulo

We investigate a coupled quintessence cosmological model in which a dark-energy scalar field with an exponential potential interacts directly with a dark-matter fluid through a dissipa tive term inspired by warm inflation. The evolution equations of this model give rise to a three dimensional dynamical system for which a thorough qualitative analysis is performed for all values of the relevant parameters. We find that the model is able to replicate the observed sequence of late-time cosmological eras, namely, a long enough matter-dominated era followed by a present era of accelerated expansion. In situations where there is a significant transfer of energy from dark energy to dark matter, temporary scaling-type solutions may arise, but, asymptotically, all solutions are dominated by dark energy.

2024-08-10Journal article

Open access