Strengthening the de Sitter swampland conjecture in warm inflation

Abstract

The de Sitter constraint on the space of effective scalar field theories consistent with superstring theory provides a lower bound on the slope of the potential of a scalar field which dominates the evolution of the Universe, e.g., a hypothetical inflaton field. Whereas models of single scalar field inflation with a canonically normalized field do not obey this constraint, it has been claimed recently in the literature that models of warm inflation can be made compatible with it in the case of large dissipation. The de Sitter constraint is known to be derived from entropy considerations. Since warm inflation necessary involves entropy production, it becomes necessary to determine how this entropy production will affect the constraints imposed by the swampland conditions. Here, we generalize these entropy considerations to the case of warm inflation and show that the condition on the slope of the potential remains essentially unchanged and is, hence, robust even in the warm inflation dynamics. We are then able to conclude that models of warm inflation indeed can be made consistent with the swampland criteria.

Stringy-running-vacuum-model inflation: from primordial gravitational waves and stiff axion matter to dynamical dark energy

“…Last but not least, we would like to discuss briefly in this section the so-called swampland criteria [135][136][137][138][139] for embedding the (stringy) RVM framework in an UV complete quantum-gravity model, such as strings. The swampland criteria refer to conditions on the potential V of scalar fields used in inflationary or other models, which, if satisfied, guarantee that the model is embeddable in string theory, which is a consistent quantumgravity framework.…”

Minimal warm inflation and TCC

“…But swampland conditions would not be relaxed in the context of warm inflation [36]. By a direct data analysis we try to find a parameter phase space of minimal warm inflation compatible with observation as well as TCC constrains.…”

Swampland constraints on no-boundary quantum cosmology

“…Alternative possibilities include multi-field dynamics[35,49], excited initial conditions[51,54], and warm inflation[55,56].3 Scalar weak gravity conjecture (scalar WGC)[69] and its variants[70,71] are another class of Swampland conjectures which may be relevant. However, the presence of many variants implies there is no clear guiding principle.…”