Weak lensing: Dark Matter, Dark Energy and Dark Gravity (2009)
In this non-specialist review I look at how weak lensing can provide information on the dark sector of the Universe. The review concentrates on what can be learned about Dark Matter, Dark Energy and...
New Optimised Estimators for the Primordial Trispectrum (2009)
Munshi, Dipak, Heavens, Alan, Cooray, Asantha, Smidt, Joseph, Coles, Peter, Serra, Paolo
Cosmic microwave background studies of non-Gaussianity involving higher-order multispectra can distinguish between early universe theories that predict nearly identical power spectra. However, the...
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...
Results of the GREAT08 Challenge: An image analysis competition for cosmological lensing (2009)
Bridle, Sarah, Balan, Sreekumar T., Bethge, Matthias, Gentile, Marc, Harmeling, Stefan, Heymans, Catherine, ...
We present the results of the GREAT08 Challenge, a blind analysis challenge to infer weak gravitational lensing shear distortions from images. The primary goal was to stimulate new ideas by...
Secondary non-Gaussianity and Cross-Correlation Analysis (2009)
Munshi, Dipak, Valageas, Patrick, Cooray, Asantha, Heavens, Alan
We develop optimised estimators of two sorts of power spectra for fields defined on the sky, in the presence of partial sky coverage. The first is the cross-power spectrum of two fields on the sky;...
Determining the Neutrino Mass Hierarchy with Cosmology (2009)
De Bernardis, Francesco, Kitching, Thomas D., Heavens, Alan, Melchiorri, Alessandro
The combination of current large scale structure and cosmic microwave background (CMB) anisotropies data can place strong constraints on the sum of the neutrino masses. Here we show that future...
Adiabatic versus Isocurvature Non--Gaussianity (2009)
Hikage, Chiaki, Munshi, Dipak, Heavens, Alan, Coles, Peter
We study the extent to which one can distinguish primordial non--Gaussianity (NG) arising from adiabatic and isocurvature perturbations. We make a joint analysis of different NG models based on...
Statistical techniques in cosmology (2009)
In these four lectures I cover a number of topics in cosmological data analysis. I concentrate on general techniques which are common in cosmology, or techniques which have been developed in a...
A New Approach to Probing Primordial Non-Gaussianity (2009)
We address the dual challenge of estimating deviations from Gaussianity arising in models of the Early Universe, whilst retaining information necessary to assess whether a detection of...
The Case for Deep, Wide-Field Cosmology (2009)
Scranton, Ryan, Albrecht, Andreas, Caldwell, Robert, Cooray, Asantha, Dore, Olivier, Habib, Salman, ...
Much of the science case for the next generation of deep, wide-field optical/infrared surveys has been driven by the further study of dark energy. This is a laudable goal (and the subject of a...
Exploring Dark Energy with Next-Generation Photometric Redshift Surveys (2009)
Zhan, Hu, Albrecht, Andreas, Cooray, Asantha, Habib, Salman, Heavens, Alan, Heitmann, Katrin, ...
The coming decade will be an exciting period for dark energy research, during which astronomers will address the question of what drives the accelerated cosmic expansion as first revealed by type Ia...
Weak gravitational lensing (2008)
In this brief review I consider the advances made in weak gravitational lensing over the last 8 years, concentrating on the large scales - cosmic shear. I outline the theoretical developments,...
Handbook for the GREAT08 Challenge: An image analysis competition for cosmological lensing (2008)
Bridle, Sarah, Shawe-Taylor, John, Amara, Adam, Applegate, Douglas, Balan, Sreekumar T., Berge, Joel, ...
The GRavitational lEnsing Accuracy Testing 2008 (GREAT08) Challenge focuses on a problem that is of crucial importance for future observations in cosmology. The shapes of distant galaxies can be used...
Bayesian Evidence for a Cosmological Constant using new High-Redshift Supernovae Data (2007)
Serra, Paolo, Heavens, Alan, Melchiorri, Alessandro
We carry out a Bayesian model selection analysis of different dark energy parametrizations using the recent luminosity distance data of high redshift supernovae from Riess et al. 2007 and from the...
Environment and the cosmic evolution of star formation (2006)
Sheth, Ravi K., Jimenez, Raul, Panter, Ben, Heavens, Alan
We present a mark correlation analysis of the galaxies in the Sloan Digital Sky Survey using weights provided by MOPED. The large size of the sample permits statistically significant statements about...
Heymans, Catherine, White, Martin, Heavens, Alan, Vale, Chris, Van Waerbeke, Ludovic
We investigate the expected correlation between the weak gravitational shear of distant galaxies and the orientation of foreground galaxies, through the use of numerical simulations. This...
Percival, Will J., Burkey, Daniel, Heavens, Alan, Taylor, Andy, Cole, Shaun, Peacock, John A., ...
We present the result of a decomposition of the 2dFGRS galaxy overdensity field into an orthonormal basis of spherical harmonics and spherical Bessel functions. Galaxies are expected to directly...
The Mass Function of the Stellar Component of Galaxies in the Sloan Digital Sky Survey (2004)
Panter, Ben, Heavens, Alan, Jimenez, Raul
Using the MOPED algorithm we determine non-parametrically the Stellar Mass Function of 96,545 galaxies from the Sloan Digital Sky Survey data release one. By using the reconstructed spectrum due to...
Jimenez, Raul, Panter, Benjamin, Heavens, Alan, Verde, Licia
Using the spectroscopic sample of the SDSS DR1 we measure how gas was transformed into stars as a function of time and stellar mass: the baryonic conversion tree (BCT). There is a clear correlation...
The Complete Star Formation History of the Universe (2004)
Heavens, Alan, Panter, Benjamin, Jimenez, Raul, Dunlop, James
The determination of the star-formation history of the Universe is a key goal of modern cosmology, as it is crucial to our understanding of how structure in the Universe forms and evolves. A picture...
Weak lensing with COMBO-17: Estimation and removal of intrinsic alignments (2004)
Heymans, Catherine, Brown, Michael, Heavens, Alan, Meisenheimer, Klaus, Taylor, Andy, Wolf, Christian
We estimate and remove the contamination of weak gravitational lensing measurements by the intrinsic alignment of close pairs of galaxies. We do this by investigating both the aperture mass B mode...
Heymans, Catherine, Heavens, Alan
We present a method for removal of the contaminating effects of intrinsic galaxy alignments, in measurements of cosmic shear from multi-colour weak lensing surveys. The method down-weights pairs...
Weak lensing with COMBO-17: estimation and removal of intrinsic alignments (2003)
Heymans, Catherine, Brown, Michael, Heavens, Alan, Meisenheimer, Klaus, Taylor, Andy, Wolf, Christian
We estimate and remove the contamination of weak gravitational lensing measurements by the intrinsic alignment of close pairs of galaxies. We do this by investigating both the aperture mass B mode...
I propose an analysis method, based on spin-spherical harmonics and spherical Bessel functions, for large-scale weak lensing surveys which have source distance information through photometric...
Weak gravitational lensing: reducing the contamination by intrinsic alignments (2002)
Heymans, Catherine, Heavens, Alan
Intrinsic alignments of galaxies can mimic to an extent the effects of shear caused by weak gravitational lensing. Previous studies have shown that for shallow surveys with median redshifts z_m =...
Recovering Physical Parameters from Galaxy Spectra Using MOPED (2001)
Reichardt, Christian, Jimenez, Raul, Heavens, Alan
We derive physical parameters of galaxies from their observed spectrum, using MOPED, the optimized data compression algorithm of Heavens, Jimenez & Lahav 2000. Here we concentrate on parametrising...
Intrinsic Correlation of Galaxy Shapes: Implications for Weak Lensing Measurements (2000)
Heavens, Alan, Refregier, Alexandre, Heymans, Catherine
Weak gravitational lensing is now established as a powerful method to measure mass fluctuations in the universe. It relies on the measurement of small coherent distortions of the images of background...
Massive Lossless Data Compression and Multiple Parameter Estimation from Galaxy Spectra (1999)
Heavens, Alan, Jimenez, Raul, Lahav, Ofer
We present a method for radical linear compression of datasets where the data are dependent on some number $M$ of parameters. We show that, if the noise in the data is independent of the parameters,...
Density and Velocity Fields from the PSCz Survey (1999)
Saunders, Will, Branchini, Enzo, Teodoro, Luis, Heavens, Alan, Taylor, Andy, Valentine, Helen, ...
We present the results for the predicted density and peculiar velocity fields and the dipole from the PSCz survey of 15,000 IRAS galaxies over 84% of the sky. We find a significant component to the...
Large-scale structure, the cosmic microwave background, and primordial non-gaussianity (1999)
Verde, Licia, Wang, Limin, Heavens, Alan, Kamionkowski, Marc
Since cosmic-microwave-background (CMB) and large-scale-structure (LSS) data will shortly improve dramatically with the Microwave Anisotropy Probe (MAP) and Planck Surveyor, and the Anglo-Australian...
Galaxy Formation and Evolution: Low Surface Brightness Galaxies (1998)
Jimenez, Raul, Padoan, Paolo, Matteucci, Francesca, Heavens, Alan
We investigate in detail the hypothesis that low surface brightness galaxies (LSB) differ from ordinary galaxies simply because they form in halos with large spin parameters. We compute star...
Eulerian bias and the galaxy density field (1997)
Mann, Bob, Peacock, John, Heavens, Alan
We investigate the effects on cosmological clustering statistics of empirical biasing, where the galaxy distribution is a local transformation of the present-day Eulerian density field. The effects...
Cosmological Parameter Estimation from the CMB (1997)
Taylor, Andy, Heavens, Alan, Ballinger, Bill, Tegmark, Max
We discuss the problems of applying Maximum Likelihood methods to the CMB and how one can make it both efficient and optimal. The solution is a generalised eigenvalue problem that allows virtually no...
First results from the PSC-z survey (1997)
Saunders, Will, Taylor, Andy, Ballinger, Bill, Heavens, Alan, Oliver, Seb, Keeble, Oliver, ...
Karhunen-Loeve eigenvalue problems in cosmology: how should we tackle large data sets? (1996)
Tegmark, Max, Taylor, Andy, Heavens, Alan
Since cosmology is no longer "the data-starved science", the problem of how to best analyze large data sets has recently received considerable attention, and Karhunen-Loeve eigenvalue methods have...