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Abstract: We consider non-minimal inflation in a gauged non-supersymmetric model containing the gravitational coupling , where denotes the Ricci scalar and the standard model singlet inflaton field Φ spontaneously breaks the symmetry. Including radiative corrections, the predictions and for the scalar spectral index and tensor to scalar ratio r lie within the current WMAP 1-σ bounds. If the symmetry breaking scale is of order a TeV or so, one of the three right handed neutrinos is a plausible cold dark matter candidate. Bounds on the dimensionless parameters λ, ξ and the gauge coupling are obtained. [Copyright &y& Elsevier]

Abstract: Minimal supersymmetric hybrid inflation utilizes a canonical Kähler potential and a renormalizable superpotential which is uniquely determined by imposing a U(1) R-symmetry. In computing the scalar spectral index we take into account modifications of the tree level potential caused by radiative and supergravity corrections, as well as contributions from the soft supersymmetry breaking terms with a negative soft mass-squared term allowed for the inflaton. All of these contributions play a role in realizing values in the range 0.96–0.97 preferred by WMAP. The U(1) R-symmetry plays an important role in flipped by eliminating the troublesome dimension five proton decay. The proton decays into via dimension six operators arising from the exchange of superheavy gauge bosons with a lifetime of order years. [Copyright &y& Elsevier]

Abstract: We discuss the important role played during inflation by one of the soft supersymmetry breaking terms in the inflationary potential of supersymmetric hybrid inflation models. With minimal Kähler potential, the inclusion of this term allows the prediction for the scalar spectral index to agree with the value found by WMAP5. In the absence of this soft term, and by taking into account only radiative and supergravity corrections, it is well known that . This same soft term has previously been shown to play a key role in resolving the MSSM μ problem. The tensor to scalar ratio r is quite small in these models, taking on values in the WMAP5 2σ range of . [Copyright &y& Elsevier]