Gravitational waves from self-ordering scalar fields (2009)
Fenu, Elisa, Figueroa, Daniel G., Durrer, Ruth, García-Bellido, Juan
21 pages, 2 figures.-- Full-text version available Open Access at the journal site.
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,...
Gravitational waves from self-ordering scalar fields (2009)
Fenu, Elisa, Figueroa, Daniel G, Durrer, Ruth, Garcia-Bellido, Juan
Gravitational waves were copiously produced in the early Universe whenever the processes taking place were sufficiently violent. The spectra of several of these gravitational wave backgrounds on...
Gravitational waves from self-ordering scalar fields (2009)
Fenu, Elisa, Figueroa, Daniel G., Durrer, Ruth, Garcia-Bellido, Juan
Gravitational waves were copiously produced in the early Universe whenever the processes taking place were sufficiently violent. The spectra of several of these gravitational wave backgrounds on...
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...
On Adiabatic Renormalization of Inflationary Perturbations (2009)
Durrer, Ruth, Marozzi, Giovanni, Rinaldi, Massimiliano
We discuss the impact of adiabatic renormalization on the power spectrum of scalar and tensor perturbations from inflation. We show that adiabatic regularization is ambiguous as it leads to very...
Braneworlds, graviton production, dynamical Casimir effect (2009)
Durrer, Ruth, Ruser, Marcus, Vonlanthen, Marc, Wittwer, Peter
If our Universe is a 3+1 brane in a warped 4+1 dimensional bulk so that its expansion can be understood as the motion of the brane in the bulk, the time dependence of the boundary conditions for...
Ruser, Marcus, Durrer, Ruth, Vonlanthen, Marc, Wittwer, Peter
In recent work by two of us, [Durrer & Ruser, PRL 99, 071601 (2007); Ruser & Durrer PRD 76, 104014 (2007)], graviton production due to a moving spacetime boundary (braneworld) in a five dimensional...
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...
CMB anisotropies from acausal scaling seeds (2009)
Scodeller, Sandro, Kunz, Martin, Durrer, Ruth
We investigate models where structure formation is initiated by scaling seeds: We consider rapidly expanding relativistic shells of energy and show that they can fit current CMB and large scale...
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...
Graviton production in non-inflationary cosmology (2009)
Durrer, Ruth, Rinaldi, Massimiliano
We discuss the creation of massless particles in a Universe, which transits from a radiation-dominated era to any other expansion law. We calculate in detail the generation of gravitons during the...
Interactions of cosmological gravitational waves and magnetic fields (2008)
The energy momentum tensor of a magnetic field always contains a spin-2 component in its anisotropic stress and therefore generates gravitational waves. It has been argued in the literature (Caprini...
Testing Lorentz Invariance Violation with WMAP Five Year Data (2008)
Kahniashvili, Tina, Durrer, Ruth, Maravin, Yurii
We consider different renormalizable models of Lorentz invariance violation. We show that the limits on birefringence of the propagation of cosmic microwave background photons from the five year data...
Is Cosmology Compatible with Blue Gravity Waves ? (2008)
Camerini, Roberta, Durrer, Ruth, Melchiorri, Alessandro, Riotto, Antonio
A primordial gravitational wave background with positive(blue) spectral index is expected in several non-standard inflationary cosmologies where the stress-energy tensor violates the null energy...
Editorial on the GRG special issue on dark energy (2008)
Ellis, George F. R., Nicolai, Hermann, Durrer, Ruth, Maartens, Roy
Angular Projections of Fractal Sets (2007)
Ruth Durrer, Jean-pierre Eckmann, Francesco Sylos Labini, Marco Montuori, Luciano Pietronero
. -- We discuss various questions which arise when one considers the central projection of three dimensional fractal sets (galaxy catalogs) onto the celestial globe. The issues are related to how...
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...
Cosmological Perturbation Theory (2004)
Abstract. This is a review on cosmological perturbation theory. After an introduction, it presents the problem of gauge transformation. Gauge invariant variables are introduced and the Einstein and...