Related papers: Gravity waves from cosmic bubble collisions
Recently it was shown that an inflationary background can be realized by any $p$-form field non-minimally coupled to gravity. In this paper, we study gravitational waves generated during p-form inflation. Even though the background…
Cosmic bubble collisions provide an important possible observational window on the dynamics of eternal inflation. In eternal inflation, our observable universe is contained in one of many bubbles formed from an inflating metastable vacuum.…
Vacuum bubbles, formed in first order phase transitions, have important implications for cosmology. In particular, they source gravitational waves. Usually, it is assumed that, once bubbles are materialized, their state, further evolution…
We perform a comprehensive study of gravitational waves in the context of the higher-order quadratic scalar curvature gravity, which encompasses the ordinary Einstein-Hilbert term in the action plus an $R^{2}$ contribution and a term of the…
If a set of massive objects collide in space and the fragments disperse, possibly forming black holes, then this process will emit gravitational waves. Computing the detailed gravitational wave-form associated with this process is a…
We study gravitational wave production during Abelian gauge-field preheating following inflation. We consider both scalar and pseudoscalar inflaton models coupled directly to Abelian gauge fields via either a dilatonic coupling to the…
We compute analytically the tidal field and polarizations of an exact gravitational wave generated by a cylindrical beam of null matter of finite width and length in quadratic curvature gravity. We propose that this wave can represent the…
We discuss the evolution of gravitational waves in a brane-world cosmology embedded in five-dimensional anti-de Sitter spacetime. We show that during slow-roll inflation, modelled as a period of quasi-de Sitter expansion on the brane, there…
We calculate the full spectrum, as observed today, of the cosmological gravitational waves generated within a model based on loop quantum cosmology. It is assumed that the universe, after the transition to the classical regime, undergoes a…
"If one could ever prove the existence of gravitational waves, the processes responsible for their generation would probably be much more curious and interesting than even the waves themselves." (Gustav Mie, 1868 - 1957) The discovery of…
We study gravitational waves generated during the inflationary epoch in presence of a decaying cosmological parameter on a 5D geometrical background which is Riemann flat. Two examples are considered, one with a constant cosmological…
In general relativity, a gravitational wave has two polarization modes (tensor mode), but it could have additional polarizations (scalar and vector modes) in the early stage of the universe, where the general relativity may not strictly…
The emission of gravitational waves from a system of massive objects interacting on elliptical, hyperbolic and parabolic orbits is studied in the quadrupole approximation. Analytical expressions are then derived for the gravitational wave…
The cosmological stochastic gravitational-wave background produced by the mildly non-linear evolution of density fluctuations is analyzed, in the frame of an Einstein-de Sitter model, by means of a fully relativistic perturbation expansion…
We calculate the gravitational waves (GW) spectrum produced in various Early Universe scenarios from gauge field sources, thus generalizing earlier inflationary calculations to bouncing cosmologies. We consider generic couplings between the…
We study gravitational-wave production from bubble collisions in a cosmic first-order phase transition, focusing on the possibility of model separation by the bubble nucleation rate dependence of the resulting gravitational-wave spectrum.…
Long-wavelength gravitational waves can induce significant temperature anisotropy in the cosmic microwave background. Distinguishing this from anisotropy induced by energy density fluctuations is critical for testing inflationary cosmology…
Gravitational wave (GW) oscillations occur whenever there are additional tensor modes interacting with the perturbations of the metric coupled to matter. These extra modes can arise from new spin-2 fields (as in e.g. bigravity theories) or…
If gaugino condensations occur in the early universe, domain walls are produced as a result of the spontaneous breaking of a discrete R symmetry. Those domain walls eventually annihilate with one another, producing the gravitational waves.…
We summarize the physical mechanism by which the Cosmic Microwave Background acquires a small degree of polarization. We discuss the imprint left by gravitational waves and the use of polarization as a test of the inflationary paradigm. We…