Bartolo, Nicola, Dimastrogiovanni, Emanuela, Matarrese, Sabino, Riotto, Antonio
Motivated by the interest in models of the early universe where statistical isotropy is broken and can be revealed in cosmological observations, we consider an SU(2) theory of gauge interactions in a...
Anisotropic bispectrum of curvature perturbations from primordial non-Abelian vector fields (2009)
Bartolo, Nicola, Dimastrogiovanni, Emanuela, Matarrese, Sabino, Riotto, Antonio
We consider a primordial SU(2) vector multiplet during inflation in models where quantum fluctuations of vector fields are involved in producing the curvature perturbation. Recently, a lot of...
Anisotropic bispectrum of curvature perturbations from primordial non-Abelian vector fields (2009)
Bartolo, Nicola, Dimastrogiovanni, Emanuela, Matarrese, Sabino, Riotto, Antonio
We consider a primordial SU(2) vector multiplet during inflation in models where quantum fluctuations of vector fields are involved in producing the curvature perturbation. Recently, a lot of...
Nitta, Daisuke, Komatsu, Eiichiro, Bartolo, Nicola, Matarrese, Sabino, Riotto, Antonio
We calculate the bispectrum of the Cosmic Microwave Background (CMB) temperature anisotropies induced by the second-order fluctuations in the Boltzmann equation. In this paper, which is one of a...
Observing the Evolution of the Universe (2009)
Aguirre, James, Amblard, Alexandre, Ashoorioon, Amjad, Baccigalupi, Carlo, Balbi, Amedeo, Bartlett, James, ...
How did the universe evolve? The fine angular scale (l>1000) temperature and polarization anisotropies in the CMB are a Rosetta stone for understanding the evolution of the universe. Through detailed...
On the non-Gaussianity from Recombination (2008)
Bartolo, Nicola, Riotto, Antonio
The non-linear effects operating at the recombination epoch generate a non-Gaussian signal in the CMB anisotropies. Such a contribution is relevant because it represents a major part of the...
CMBPol Mission Concept Study: Probing Inflation with CMB Polarization (2008)
Baumann, Daniel, Jackson, Mark G, Adshead, Peter, Amblard, Alexandre, Ashoorioon, Amjad, Bartolo, Nicola, ...
We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to...
CMBPol Mission Concept Study: Probing Inflation with CMB Polarization (2008)
Baumann, Daniel, Jackson, Mark G., Adshead, Peter, Amblard, Alexandre, Ashoorioon, Amjad, Bartolo, Nicola, ...
We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to...
One-loop graviton corrections to the curvature perturbation from inflation (2008)
Dimastrogiovanni, Emanuela, Bartolo, Nicola
We compute one-loop corrections to the power spectrum of the curvature perturbation in single-field slow-roll inflation arising from gravitons and inflaton interactions. The quantum corrections due...
How the Scalar Field of Unified Dark Matter Models Can Cluster (2008)
Bertacca, Daniele, Bartolo, Nicola, Diaferio, Antonaldo, Matarrese, Sabino
We use scalar-field Lagrangians with a non-canonical kinetic term to obtain unified dark matter models where both the dark matter and the dark energy, the latter mimicking a cosmological constant,...
CMB temperature anisotropies from third-order gravitational perturbations (2008)
D'Amico, Guido, Bartolo, Nicola, Matarrese, Sabino, Riotto, Antonio
In this paper we present a complete computation of the Cosmic Microwave Background (CMB) anisotropies up to third order from gravitational perturbations accounting for scalar, vector and tensor...
Halos of Unified Dark Matter Scalar Field (2007)
Bertacca, Daniele, Bartolo, Nicola, Matarrese, Sabino
We investigate the static and spherically symmetric solutions of Einstein's equations for a scalar field with non-canonical kinetic term, assumed to provide both the dark matter and dark energy...
ISW effect in Unified Dark Matter Scalar Field Cosmologies: an analytical approach (2007)
Bertacca, Daniele, Bartolo, Nicola
We perform an analytical study of the Integrated Sachs-Wolfe (ISW) effect within the framework of Unified Dark Matter models based on a scalar field which aim at a unified description of dark energy...
Cosmic Microwave Background Anisotropies up to Second Order (2007)
Bartolo, Nicola, Matarrese, Sabino, Riotto, Antonio
These lecture notes present the computation of the full system of Boltzmann equations describing the evolution of the photon, baryon and cold dark matter fluids up to second order in perturbation...
Cosmic Microwave Background Anisotropies up to Second Order (2007)
Bartolo, Nicola, Matarrese, Sabino, Riotto, Antonio
These lecture notes present the computation of the full system of Boltzmann equations describing the evolution of the photon, baryon and cold dark matter fluids up to second order in perturbation...
B-mode polarization of the CMB from the second-order photon quadrupole (2007)
Bartolo, Nicola, Matarrese, Sabino, Mollerach, Silvia, Riotto, Antonio
We study a new contribution to the polarization of the Cosmic Microwave Background induced at the epoch of recombination by the second-order quadrupole moment of the photon distribution. At second...
CMB Anisotropies at Second-Order II: Analytical Approach (2006)
Bartolo, Nicola, Matarrese, Sabino, Riotto, Antonio
We provide an analytical approach to the second-order Cosmic Microwave Background (CMB) anisotropies generated by the non-linear dynamics taking place at last scattering. We study the acoustic...
Perturbations in cosmologies with a scalar field and a perfect fluid (2003)
Bartolo, Nicola, Corasaniti, Pier-Stefano, Liddle, Andrew R., Malquarti, Michaël
We study the properties of cosmological density perturbations in a multi-component system consisting of a scalar field and a perfect fluid. We discuss the number of degrees of freedom completely...
An Observational Test of Two-field Inflation (2002)
Wands, David, Bartolo, Nicola, Matarrese, Sabino, Riotto, Antonio
We study adiabatic and isocurvature perturbation spectra produced by a period of cosmological inflation driven by two scalar fields. We show that there exists a model-independent consistency...
Scalar-Tensor Gravity and Quintessence (1999)
Bartolo, Nicola, Pietroni, Massimo
Scalar fields with inverse power-law effective potentials may provide a negative pressure component to the energy density of the universe today, as required by cosmological observations. In order to...