Revisiting Witten-O'Raifeartaigh inflation for a non-minimally coupled scalar field

Abstract

Abstract In this work, we revisit the Witten-O'Raifeartaigh model of inflation, in which the potential takes a log2(ϕ/M) form, when the scalar field is non-minimally coupled to gravity. We investigate the impact of the coupling in the prediction of the inflationary parameters, thereby affecting the viability of the model. We find that a small coupling of order ξ ∼ 10-3 is preferred by data at the ns-r plane level, and that the presence of a non-zero ξ allows for a large interval of the mass scale M, in which it is possible to achieve a low tensor-to-scalar ratio. We also establish constraints imposed by a subsequent reheating era, in which its duration and temperature can be related to CMB observables, which in return, restricts the possible values for the ns and r parameters.