Emanuela Dimastrogiovanni

Non-Gaussianity and Statistical Anisotropy from Vector Field Populated Inflationary Models

We present a review of vector field models of inflation and, in particular, of the statistical anisotropy and non-Gaussianity predictions of models with SU(2) vector multiplets. Non-Abelian gauge groups introduce a richer amount of predictions compared to the Abelian ones, mostly because of the presence of vector fields self-interactions. Primordial vector fields can violate isotropy leaving their imprint in the comoving curvature fluctuations 𝜁 at late times. We provide the analytic expressions of the correlation functions of 𝜁 up to fourth order and an analysis of their amplitudes and shapes. The statistical anisotropy signatures expected in these models are important and, potentially, the anisotropic contributions to the bispectrum and the trispectrum can overcome the isotropic parts.

Reheating predictions in single field inflation

Reheating is a transition era after the end of inflation, during which the inflaton is converted into the particles that populate the Universe at later times. No direct cosmological observables are normally traceable to this period of reheating. Indirect bounds can however be derived. One possibility is to consider cosmological evolution for observable CMB scales from the time of Hubble crossing to the present time. Depending upon the model, the duration and final temperature after reheating, as well as its equation of state, may be directly linked to inflationary observables. For single-field inflationary models, if we approximate reheating by a constant equation of state, one can derive relations between the reheating duration (or final temperature), its equation of state parameter, and the scalar power spectrum amplitude and spectral index. While this is a simple approximation, by restricting the equation of state to lie within a broad physically allowed range, one can in turn bracket an allowed range of

Inflationary tensor fossils in large-scale structure

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Low-energy effective field theory for chromo-natural inflation

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Gauge-flation confronted with Planck

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Probing the scale dependence of non-Gaussianity with spectral distortions of the cosmic microwave background

for these models. The added constraints can help break degeneracies between inflation models that otherwise overlap in their predictions for

Primordial Gravitational Waves from Axion-Gauge Fields Dynamics

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Gravitational Waves and Scalar Perturbations from Spectator Fields

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Possible signatures of the inflationary particle content: spin-2 fields

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Constraints on gravitino decay and the scale of inflation using CMB spectral distortions

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