Related papers: Reconstructing the Inflaton Potential

These lecture notes provide a brief introduction to methods used to search for a stochastic background of gravitational radiation -- a superposition of gravitational-wave signals that are either too weak or too numerous to individually…

Under certain conditions, the oscillating inflaton condensate filling the Universe after inflation can fragment and form so-called oscillons. These long-lived soliton-like field configurations can dominate the Universe for several $e$-folds…

The Stochastic Gravitational Wave Background (SGWB) is expected to be a key observable for Gravitational Wave (GW) interferometry. Its detection will open a new window on early universe cosmology and on the astrophysics of compact objects.…

The recently detected stochastic signal by several pulsar timing array collaborations, offers an opportunity to scrutinize the fundamental properties of gravity, including the potential mass of the graviton. In this study, we analyze the…

We present a supergravity inflationary scenario in which the inflaton field takes values considerably larger than the Planck scale. It is based on a class of inflationary potentials which can be derived from ``singular'' Kaehler potentials…

We report results from searches for anisotropic stochastic gravitational-wave backgrounds using data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors. For the first time, we include Virgo data in our…

In this work we highlight an important perspective for the complete understanding of the stochastic gravitational background structure. The stochastic gravitational wave background is perhaps the most important current and future tool…

We investigate the stochastic gravitational wave (GW) spectrum resulting from graviton bremsstrahlung during inflationary reheating. We focus on an inflaton $\phi$ oscillating around a generic monomial potential $V(\phi) \propto \phi^n$,…

It is well-known that first order phase transitions in the early universe can be a powerful source of observable stochastic gravitational wave backgrounds. Any such gravitational wave background must exhibit large-scale anisotropies at…

We present the results of simulated injections testing the first Bayesian search-pipeline capable of investigating the angular-structure of a gravitational-wave (GW) background influencing pulsar signals. A stochastic background of GWs from…

Could COBE DMR be detecting the imprint from a spectrum of gravitational waves generated during inflation? The conventional inflationary prediction had been that the cosmic microwave anisotropy is dominated by energy density fluctuations…

We construct a hybrid-inflation model where the inflaton potential is generated radiatively, as gauge symmetries guarantee it to be accidentally flat at tree level. The model can be regarded as a small-field version of Natural Inflation,…

Using second-order gauge-invariant perturbation theory, a self-consistent framework describing the non-linear coupling between gravitational waves and a large-scale homogeneous magnetic field is presented. It is shown how this coupling may…

In this work, we investigate the possibility that supersymmetric structures may leave observable imprints in the stochastic gravitational-wave (GW) background generated during the reheating era. To this end, we construct a phenomenological…

Inhomogeneous multidimensional cosmological models with a higher dimensional space-time manifold are investigated under dimensional reduction. In the Einstein conformal frame, small excitations of the scale factors of the internal spaces…

It is shown that a system of two coupled planar material sheets possessing surface mode (polariton) resonances can be used for the purpose of evanescent field restoration and, thus, for the sub-wavelength near-field imaging. The sheets are…

We demonstrate that cosmological perturbations can undergo amplification by parametric resonance during the preheating period following inflation, even on scales larger than the Hubble radius, without violating causality. A unified…

In a recent paper, which has been published in Nature, the LIGO Scientific Collaboration (LSC) obtained an upper limit on the stochastic gravitational-wave background of cosmological origin by using the data from a two-year science run of…

We present a brief review of the polarization properties of the cosmic microwave background in dark matter models for structure formation. Quite independently of the model parameters, the polarization level is expected to be $\sim 10%$ of…

The universe may have extra spatial dimensions with large volume that we cannot perceive because the energy required to excite modes in the extra directions is too high. Many examples are known of such manifolds with a large volume and a…