Caprini, Chiara, Durrer, Ruth, Servant, Geraldine
We analytically derive the spectrum of gravitational waves due to magneto-hydrodynamical turbulence generated by bubble collisions in a first-order phase transition. In contrast to previous studies,...
Can the observed large scale magnetic fields be seeded by helical primordial fields? (2009)
Caprini, Chiara, Durrer, Ruth, Fenu, Elisa
Gravitational wave production induces a strong constraint on the amplitude of a primordial magnetic field. It has been shown that the nucleosynthesis bound for a stochastic gravitational wave...
Caprini, Chiara, Finelli, Fabio, Paoletti, Daniela, Riotto, Antonio
We evaluate the angular bispectrum of the CMB temperature anisotropy at large angular scale due to a stochastic background of primordial magnetic fields. The shape of non-Gaussianity depends on the...
General Properties of the Gravitational Wave Spectrum from Phase Transitions (2009)
Caprini, Chiara, Durrer, Ruth, Konstandin, Thomas, Servant, Geraldine
In this paper we discuss some general aspects of the gravitational wave background arising from post-inflationary short-lasting cosmological events such as phase transitions. We concentrate on the...
General Properties of the Gravitational Wave Spectrum from Phase Transitions (2009)
Caprini, Chiara, Durrer, Ruth, Konstandin, Thomas, Servant, Geraldine
In this paper we discuss some general aspects of the gravitational wave background arising from post-inflationary short-lasting cosmological events such as phase transitions. We concentrate on the...
Dirac Born Infeld (DBI) Cosmic Strings (2008)
Babichev, Eugeny, Brax, Philippe, Caprini, Chiara, Martin, Jerome, Steer, Daniele
Motivated by brane physics, we consider the non-linear Dirac-Born-Infeld (DBI) extension of the Abelian-Higgs model and study the corresponding cosmic string configurations. The model is defined by a...
Dirac Born Infeld (DBI) Cosmic Strings (2008)
Babichev, Eugeny, Brax, Philippe, Caprini, Chiara, Martin, Jerome, Steer, Daniele
Motivated by brane physics, we consider the non-linear Dirac-Born-Infeld (DBI) extension of the Abelian-Higgs model and study the corresponding cosmic string configurations. The model is defined by a...
Optimising large galaxy surveys for ISW detection (2008)
Douspis, Marian, Castro, Patricia G., Caprini, Chiara, Aghanim, Nabila
We report on investigations of the power of next generation cosmic microwave background and large scale structure surveys in constraining the nature of dark energy through the cross-correlation of...
Challenges for creating magnetic fields by cosmic defects (2007)
Hollenstein, Lukas, Caprini, Chiara, Crittenden, Robert, Maartens, Roy
We analyse the possibility that topological defects can act as a source of magnetic fields through the Harrison mechanism in the radiation era. We give a detailed relativistic derivation of the...
Caprini, Chiara, Durrer, Ruth, Servant, Géraldine
Gravitational wave production from bubble collisions was calculated in the early nineties using numerical simulations. In this paper, we present an alternative analytic estimate, relying on a...
Caprini, Chiara, Durrer, Ruth, Servant, Geraldine
Gravitational wave production from bubble collisions was calculated in the early nineties using numerical simulations. In this paper, we present an alternative analytic estimate, relying on a...
Superluminal motion and closed signal curves (2007)
Bonvin, Camille, Caprini, Chiara, Durrer, Ruth
We discuss some properties of Lorentz invariant theories which allow for superluminal motion. We show that, if signals are always sent forward in time, closed curves along which signals propagate can...
On the frequency of gravitational waves (2006)
Caprini, Chiara, Durrer, Ruth, Sturani, Riccardo
We show that there are physically relevant situations where gravitational waves do not inherit the frequency spectrum of their source but its wavenumber spectrum.
No-go theorem for k-essence dark energy (2006)
Bonvin, Camille, Caprini, Chiara, Durrer, Ruth
We demonstrate that if k-essence can solve the coincidence problem and play the role of dark energy in the universe, the fluctuations of the field have to propagate superluminally at some stage. We...
The power spectrum of a homogeneous and isotropic stochastic variable, characterized by a finite correlation length, does in general not vanish on scales larger than the correlation scale. If the...
Limits on stochastic magnetic fields: A defense of our paper [1] (2005)
In their recent paper ``Faraday rotation of the cosmic microwave background polarization by a stochastic magnetic field'', Kosowsky et al. Phys.Rev. D71, 043006 (2005) have commented about our paper...
The observational consequences of primordial fields / (2004)
BLDSC reference no.: D230258.
Primordial Magnetic Fields and Causality (2003)
We discuss the implications of causality on a primordial magnetic field. We show that the residual field on large scales is much more suppressed than usually assumed and that a helical component is...
The Cosmic Microwave Background and Helical Magnetic Fields: the tensor mode (2003)
Caprini, Chiara, Durrer, Ruth, Kahniashvili, Tina
We study the effect of a possible helicity component of a primordial magnetic field on the tensor part of the cosmic microwave background temperature anisotropies and polarization. We give analytical...
Gravitational wave production: A strong constraint on primordial magnetic fields (2001)
We compute the gravity waves induced by anisotropic stresses of stochastic primordial magnetic fields. The nucleosynthesis bound on gravity waves is then used to derive a limit on the magnetic field...