Scientific Commons: Alexandre Amblard

The Impact of Secondary non-Gaussianities in the CMB on Cosmological Parameter Estimation (2009)

Smidt, Joseph, Joudaki, Shahab, Serra, Paolo, Amblard, Alexandre, Cooray, Asantha

We consider corrections to the cosmological parameters due to secondary contributions from weak gravitational lensing, the integrated Sachs-Wolfe effect, and the Sunyaev-Zel'dovich effect contained...

Non-Gaussianity in WMAP Data Due to the Correlation of CMB Lensing Potential with Secondary Anisotropies (2009)

Calabrese, Erminia, Smidt, Joseph, Amblard, Alexandre, Cooray, Asantha, Melchiorri, Alessandro, Serra, Paolo, ...

We measure the skewness power spectrum of the Cosmic Microwave Background (CMB) anisotropies optimized for a detection of the secondary bispectrum generated by the correlation of the CMB lensing...

A Measurement of Primordial Non-Gaussianity Using WMAP 5-Year Temperature Skewness Power Spectrum (2009)

Smidt, Joseph, Amblard, Alexandre, Serra, Paolo, Cooray, Asantha

We constrain the primordial non-Gaussianity parameter of the local model f_{NL} using the skewness power spectrum associated with the two-to-one cumulant correlator of cosmic microwave background...

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...

A New Era in Extragalactic Background Light Measurements: The Cosmic History of Accretion, Nucleosynthesis and Reionization (2009)

Cooray, Asantha, Amblard, Alexandre, Beichman, Charles, Benford, Dominic, Bernstein, Rebecca, Bock, James, ...

(Brief Summary) What is the total radiative content of the Universe since the epoch of recombination? The extragalactic background light (EBL) spectrum captures the redshifted energy released from...

Cosmic reionization and the 21 cm signal: comparison between an analytical model and a simula (2008)

Santos, Mário G., Amblard, Alexandre, Pritchard, Jonathan, Trac, Hy, Cen, Renyue, Cooray, Asantha

We measure several properties of the reionization process and the corresponding low-frequency 21 cm signal associated with the neutral hydrogen distribution, using a large volume, high-resolution...

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...

Needlet Detection of Features in WMAP CMB Sky and the Impact on Anisotropies and Hemispherical Asymmetries (2008)

Pietrobon, Davide, Amblard, Alexandre, Balbi, Amedeo, Cabella, Paolo, Cooray, Asantha, Marinucci, Domenico

We apply spherical needlets to the Wilkinson Microwave Anisotropy Probe 5-year cosmic microwave background (CMB) dataset, to search for imprints of non-isotropic features in the CMB sky. We use the...

Implications of Two Type Ia Supernova Populations for Cosmological Measurements (2008)

Sarkar, Devdeep, Amblard, Alexandre, Cooray, Asantha, Holz, Daniel E.

Recent work suggests that Type Ia supernovae (SNe) are composed of two distinct populations: prompt and delayed. By explicitly incorporating properties of host galaxies, it may be possible to target...

Impact of Point Source Clustering on Cosmological Parameters with CMB Anisotropies (2008)

Serra, Paolo, Cooray, Asantha, Amblard, Alexandre, Pagano, Luca, Melchiorri, Alessandro

The faint radio point sources that are unresolved in cosmic microwave background (CMB) anisotropy maps are likely to be a biased tracer of the large-scale structure dark matter distribution. While...

Lensing and Supernovae: Quantifying The Bias on the Dark Energy Equation of State (2007)

Sarkar, Devdeep, Amblard, Alexandre, Holz, Daniel E., Cooray, Asantha

The gravitational magnification and demagnification of Type Ia supernovae (SNe) modify their positions on the Hubble diagram, shifting the distance estimates from the underlying luminosity-distance...

Beyond Two Dark Energy Parameters (2007)

Sarkar, Devdeep, Sullivan, Scott, Joudaki, Shahab, Amblard, Alexandre, Holz, Daniel E., Cooray, Asantha

Our ignorance of the dark energy is generally described by a two-parameter equation of state. In these approaches a particular {\it ad hoc} functional form is assumed, and only two independent...

Cosmic Reionization and the 21-cm signal: Comparison between an analytical model and a simulation (2007)

Santos, Mario G., Amblard, Alexandre, Pritchard, Jonathan, Trac, Hy, Cen, Renyue, Cooray, Asantha

We measure several properties of the reionization process and the corresponding low-frequency 21-cm signal associated with the neutral hydrogen distribution, using a large volume, high resolution...

Anisotropy Studies of the Unresolved Far-infrared Background (2007)

Amblard, Alexandre, Cooray, Asantha

Dusty, starforming galaxies and active galactic nuclei that contribute to the integrated background intensity at far-infrared wavelengths trace the large-scale structure. Below the point source...

Search for Gravitational Waves in the CMB After WMAP3: Foreground Confusion and The Optimal Frequency Coverage for Foreground Minimization (2006)

Amblard, Alexandre, Cooray, Asantha, Kaplinghat, Manoj

B-modes of Cosmic Microwave Background (CMB) polarization can be created by a primordial gravitational wave background. If this background was created by Inflation, then the amplitude of the...

Weak Lensing of the CMB by Large-Scale Structure (2004)

Amblard, Alexandre, Vale, Chris, White, Martin

Several recent papers have studied lensing of the CMB by large-scale structures, which probes the projected matter distribution from $z=10^3$ to $z\simeq 0$. This interest is motivated in part by...

Cluster Lensing of the CMB (2004)

Vale, Chris, Amblard, Alexandre, White, Martin

We investigate what the lensing information contained in high resolution, low noise CMB temperature maps can teach us about cluster mass profiles. We create lensing fields and Sunyaev-Zel'dovich...

Noise power spectrum estimation and fast map making for CMB experiments (2003)

Amblard, Alexandre, Hamilton, Jean-Christophe

We present a method designed to estimate the noise power spectrum in the time domain for CMB experiments. The noise power spectrum is extracted from the time ordered data avoiding the contamination...

Noise power spectrum estimation and fast map making for CMB experiments (2003)

Amblard, Alexandre, Hamilton, Jean-Christophe

We present a method designed to estimate the noise power spectrum in the time domain for CMB experiments. The noise power spectrum is extracted from the time ordered data avoiding the contamination...

Analyse des anisotropies du fond diffus cosmologique dans le cadre de l'expérience ARCHEOPS (2002)

Amblard, Alexandre