Related papers: Very-High-Frequency Gravitational Waves from Multi…
We investigate the production of gravitational waves during preheating after inflation in the common case of field potentials that are asymmetric around the minimum. In particular, we study the impact of oscillons, comparatively long lived…
We consider gravitational wave production due to parametric resonance at the end of inflation, or ``preheating''. This leads to large inhomogeneities which source a stochastic background of gravitational waves at scales inside the comoving…
Phase transitions during inflation can generate a stochastic gravitational-wave background that probes primordial physics. We study the detectability and parameter reconstruction of such a signal with a space-based gravitational-wave…
Inflation models ending in a first order phase transition produce gravitational waves (GW) via bubble collisions of the true vacuum phase. We demonstrate that these bubble collisions can leave an observable signature in Advanced LIGO, an…
In warm inflation, dissipation due to the interactions of the inflaton field to other light degrees of freedom leads naturally to the enhancement of the primordial spectrum during the last 10-20 efolds of inflation. We study this effect in…
Chain inflation proceeds through a series of first order phase transitions, which can release considerable gravitational waves (GW). We demonstrate that bubble collisions can leave an observable signature for future high-frequency probes of…
During inflation long wavelength gravitational waves are produced, which form stochastic background in the present universe with very wide range of frequencies. Higher frequency gravitational waves never experience super-Hubble-radius…
Observations of anisotropies in the cosmic microwave background by the Wilkinson Microwave Anisotropy Probe suggest the possibility of oscillations in the primordial density perturbation. Such deviations from the usually assumed scale-free…
We study the inflationary gravitational wave background induced by Abelian gauge fields generated by non-minimal kinetic and axial couplings to the inflaton. We show that, up to slow-roll corrections, for coupling functions that share the…
We re-examine the gravitational wave background resulting from inflation and its effect on the cosmic microwave background radiation. The new COBE measurement of a cosmic background quadrupole anisotropy places an upper limit on the vacuum…
In many models of inflation, the period of accelerated expansion ends with preheating, a highly non-thermal phase of evolution during which the inflaton pumps energy into a specific set of momentum modes of field(s) to which it is coupled.…
We consider the impact of thermal inflation -- a short, secondary period of inflation that can arise in supersymmetric scenarios -- on the stochastic gravitational wave background. We show that while the primordial inflationary…
We study the production, spectrum and detectability of gravitational waves in models of the early Universe where first order phase transitions occur during inflation. We consider all relevant sources. The self-consistency of the scenario…
We investigate the properties of gravitational waves generated by heating induced phase transitions in warm inflation. In this scenario, the heating phase of inflation followed by subsequent cosmological cooling can trigger two associated…
The reheating of the universe after hybrid inflation proceeds through the nucleation and subsequent collision of large concentrations of energy density in the form of bubble-like structures moving at relativistic speeds. This generates a…
Physical scenarios, leading to highly energetic stochastic gravitational waves backgrounds (for frequencies ranging from the $\mu$Hz up to the GHz) are examined. In some cases the typical amplitude of the logarithmic energy spectrum can be…
Due to the universality of gravitational interactions, it is generally expected that a stochastic gravitational wave (GW) background could form during the reheating period when the inflaton perturbatively decays with the emission of…
The longitudinal components of massive vector fields generated during inflation constitute a well-motivated dark matter candidate, with interesting phenomenological implications. During the epoch of radiation domination following inflation,…
We investigate the inhomogeneous inflation, in which the space exponentially expands with inhomogeneities, and its cosmological perturbations. The inhomogeneous inflation is realized by introducing scalar fields with spacelike gradients…
Electromagnetic methods recently proposed for detecting gravitational waves modify the Michelson phase shift analysis (historically employed for special relativity). We suggest that a frequency modulation analysis is more suited to general…