Publications (64)
New Dimensions in Cosmic Lensing
Andy Taylor
I review the current status of combing weak gravitational lensing with depth information from redshifts as a direct probe of dark matter and dark energy in the Universe. In particu…
The STAGES view of red spirals and dusty red galaxies: Mass-dependent quenching of star-formation in cluster infall
Christian Wolf, Alfonso Aragon-Salamanca, Michael Balogh +22
We investigate the properties of optically passive spirals and dusty red galaxies in the A901/2 cluster complex at redshift ~0.17 using restframe near-UV-optical SEDs, 24 micron IR…
Visualization of gene expression information within the context of the mouse anatomy
Andy Taylor, Kenneth McLeod, Chris Armit +2
Background: The eMouse Atlas of Gene Expression (EMAGE) is an online resource that publishes the results of in situ gene expression experiments on the developmental mouse. The reso…
The impact of baryons on the sensitivity of dark energy measurements
David Copeland, Andy Taylor, Alex Hall
Baryonic effects on large-scale structure, if not accounted for, can significantly bias dark energy constraints. As the detailed physics of the baryons is not yet well-understood,…
Cosmological Parameter Estimation from the CMB
Andy Taylor, Alan Heavens, Bill Ballinger +1
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…
Impact of weak lensing on bright standard siren analyses
Charlie T. Mpetha, Giuseppe Congedo, Andy Taylor +1
Gravitational waves from binary mergers at cosmological distances will experience weak lensing by large scale structure. This causes a (de-)magnification, , of the wave amplitu…
Dark Matter Astrometry: Accuracy of sub-halo positions for the measurement of self-interaction cross sections
David Harvey, Richard Massey, Thomas Kitching +5
Direct evidence for the existence of dark matter and measurements of its interaction cross-section have been provided by the physical offset between dark matter and intra- cluster…
The 2dF Galaxy Redshift Survey: Spherical Harmonics analysis of fluctuations in the final catalogue
Will J. Percival, Daniel Burkey, Alan Heavens +26
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 expect…
Joint cosmological inference of standard sirens and gravitational wave weak lensing
Giuseppe Congedo, Andy Taylor
We present the first joint inference of standard sirens and gravitational wave weak lensing by filtering of the same dataset. We imagine a post-LISA scenario emerging around the la…
Classifying Linearly Shielded Modified Gravity Models in Effective Field Theory
Lucas Lombriser, Andy Taylor
We study the model space generated by the time-dependent operator coefficients in the effective field theory of the cosmological background evolution and perturbations of modified…
Scientific Synergy Between LSST and Euclid
Jason Rhodes, Robert C. Nichol, Ãric Aubourg +34
Euclid and the Large Synoptic Survey Telescope (LSST) are poised to dramatically change the astronomy landscape early in the next decade. The combination of high cadence, deep, wid…
Less than 10 percent of star formation in z=0.6 massive galaxies is triggered by major interactions
Aday R. Robaina, Eric F. Bell, Rosalind E. Skelton +26
Both observations and simulations show that major tidal interactions or mergers between gas-rich galaxies can lead to intense bursts of starformation. Yet, the average enhancement…
Future prospects on testing extensions to CDM through the weak lensing of gravitational waves
Charlie T. Mpetha, Giuseppe Congedo, Andy Taylor
With planned space-based and 3rd generation ground-based gravitational wave detectors (LISA, Einstein Telescope, Cosmic Explorer), and proposed DeciHz detectors (DECIGO, Big Bang O…
Semi-dynamical perturbations of unified dark energy
Lucas Lombriser, Andy Taylor
Linear cosmological perturbations of a large class of modified gravity and dark energy models can be unified in the effective field theory of cosmic acceleration, encompassing Horn…
Estimating Cosmological Parameter Covariance
Andy Taylor, Benjamin Joachimi
We investigate the bias and error in estimates of the cosmological parameter covariance matrix, due to sampling or modelling the data covariance matrix, for likelihood width and pe…
A Bayesian method for combining theoretical and simulated covariance matrices for large-scale structure surveys
Alex Hall, Andy Taylor
Accurate and precise covariance matrices will be important in enabling planned cosmological surveys to detect new physics. Standard methods imply either the need for many N-body si…
A minimal self tuning model to solve the cosmological constant problem
Arnaz Khan, Andy Taylor
The expansion of the Universe is observed to be accelerating, with the simplest solution being a classical cosmological constant. However, this receives contributions from the quan…
Errors on errors - Estimating cosmological parameter covariance
Benjamin Joachimi, Andy Taylor
Current and forthcoming cosmological data analyses share the challenge of huge datasets alongside increasingly tight requirements on the precision and accuracy of extracted cosmolo…
On the large-scale instability in interacting dark energy and dark matter fluids
Brendan M Jackson, Andy Taylor, Arjun Berera
Recently, Valiviita et al. (2008) have reported a large-scale early-time instability in coupled dark energy and dark matter models. We take the same form of energy-momentum exchang…
Illuminating the Physics of Cosmic Origin and Evolution: A UK Space Frontiers 2035 White Paper
Florian Beutler, Eva-Maria Mueller, Seshadri Nadathur +61
Understanding the Universe's origins and evolution remains one of the most fundamental challenges in modern cosmology. This white paper explores three key science priorities in thi…
Is Gravitational Lensing by Intercluster Filaments Always Negligible?
Martin Feix, Dong Xu, HuanYuan Shan +4
Intercluster filaments negligibly contribute to the weak lensing signal in general relativity (GR), . In the context of relativistic modified Newtonian…
Prospects for galaxy-mass relations from the 6dF Galaxy Survey
Daniel Burkey, Andy Taylor
We develop new methods to study the properties of galaxy redshift surveys and radial peculiar velocity surveys, both individually and combined. We derive the Fisher information mat…
Screening and degenerate kinetic self-acceleration from the nonlinear freedom of reconstructed Horndeski theories
Joe Kennedy, Lucas Lombriser, Andy Taylor
We have previously presented a reconstruction of Horndeski scalar-tensor theories from linear cosmological observables. It includes free nonlinear terms which can be added onto the…
Cosmic shear measurement with maximum likelihood and maximum a posteriori inference
Alex Hall, Andy Taylor
We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and comp…
Weak Lensing from Space II: Dark Matter Mapping
Richard Massey, Jason Rhodes, Alexandre Refregier +8
We study the accuracy with which weak lensing measurements could be made from a future space-based survey, predicting the subsequent precisions of 3-dimensional dark matter maps, p…
Testing Quadratic Maximum Likelihood estimators for forthcoming Stage-IV weak lensing surveys
Alessandro Maraio, Alex Hall, Andy Taylor
Headline constraints on cosmological parameters from current weak lensing surveys are derived from two-point statistics that are known to be statistically sub-optimal, even in the…
Putting the Precision in Precision Cosmology: How accurate should your data covariance matrix be?
Andy Taylor, Benjamin Joachimi, Thomas Kitching
Cosmological parameter estimation requires that the likelihood function of the data is accurately known. Assuming that cosmological large-scale structure power spectra data are mul…
Reconstructing PSCz with a Generalized PIZA
Helen E. M. Valentine, Will Saunders, Andy Taylor
We present a generalized version of the Path Interchange Zel'dovich Approximation (PIZA; Croft and Gaztanaga 1997; hereafter CG97), which may be used to reconstruct density and vel…
Inherently stable effective field theory for dark energy and modified gravity
Lucas Lombriser, Charles Dalang, Joe Kennedy +1
The growing wealth of cosmological observations places increasingly more stringent constraints on dark energy and alternative gravity models. Particularly successful in efficiently…
Unfolding the matter distribution using 3-D weak gravitational lensing
Patrick Simon, Andy Taylor, Jan Hartlap
Combining redshift and galaxy shape information offers new exciting ways of exploiting the gravitational lensing effect for studying the large scales of the cosmos. One application…
Gravitational Lensing Accuracy Testing 2010 (GREAT10) Challenge Handbook
Thomas Kitching, Sreekumar Balan, Gary Bernstein +32
GRavitational lEnsing Accuracy Testing 2010 (GREAT10) is a public image analysis challenge aimed at the development of algorithms to analyze astronomical images. Specifically, the…
Weak lensing with COMBO-17: estimation and removal of intrinsic alignments
Catherine Heymans, Michael Brown, Alan Heavens +3
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 aper…
Breaking a Dark Degeneracy with Gravitational Waves
Lucas Lombriser, Andy Taylor
We identify a scalar-tensor model embedded in the Horndeski action whose cosmological background and linear scalar fluctuations are degenerate with the concordance cosmology. The m…
A Generalized Method for Measuring Weak Lensing Magnification With Weighted Number Counts
Bryan Gillis, Andy Taylor
We present a derivation of a generalized optimally-weighted estimator for the weak lensing magnification signal, including a calculation of errors. With this estimator, we present…
Cosmological Perturbations and Quasi-Static Assumption in Theories
Mu-Chen Chiu, Andy Taylor, Chenggang Shu +1
gravity is one of the simplest theories of modified gravity to explain the accelerated cosmic expansion. Although it is usually assumed that the quasi-Newtonian approach (a…
Dark matter maps reveal cosmic scaffolding
Richard Massey, Jason Rhodes, Richard Ellis +17
Ordinary baryonic particles (such as protons and neutrons) account for only one-sixth of the total matter in the Universe. The remainder is a mysterious "dark matter" component, wh…
STAGES: the Space Telescope A901/2 Galaxy Evolution Survey
M. E. Gray, Christian Wolf, Marco Barden +26
We present an overview of the Space Telescope A901/2 Galaxy Evolution Survey (STAGES). STAGES is a multiwavelength project designed to probe physical drivers of galaxy evolution ac…
Parameter information from nonlinear cosmological fields
Andy Taylor, Peter Watts
We develop a general formalism for analysing parameter information from non-Gaussian cosmic fields. The method can be adapted to include the nonlinear effects in galaxy redshift su…
The Inverse Redshift-Space Operator: Reconstructing Cosmological Density and Velocity Fields
Andy Taylor, Helen Valentine
We present the linear inverse redshift space operator which maps the galaxy density field derived from redshift surveys from redshift space to real space. Expressions are presented…
The consistency relation in braneworld inflation
David Seery, Andy Taylor
The braneworld cosmology, in which our universe is imbedded as a hypersurface in a higher dimensional bulk, has the peculiar property that the inflationary consistency relation der…
A Weak Lensing Detection of the Cosmological Distance-Redshift Relation Behind Three Massive Clusters
Elinor Medezinski, Tom Broadhurst, Keiichi Umetsu +2
The amplitude of weak lensing should increase with source distance, rising steeply behind a lens and saturating at high redshift, providing a model-independent means of measuring c…
Cosmological weak lensing with the HST GEMS survey
Catherine Heymans, Michael L. Brown, Marco Barden +16
We present our cosmic shear analysis of GEMS, one of the largest wide-field surveys ever undertaken by the Hubble Space Telescope. Imaged with the Advanced Camera for Surveys (ACS)…
The clustering of warm and cool IRAS galaxies
Bob Mann, Will Saunders, Andy Taylor
We use a series of statistical techniques to compare the clustering of samples of IRAS galaxies selected on the basis of their far-infrared emission temperature, to see whether a t…
Flat-Sky Pseudo-Cls Analysis for Weak Gravitational Lensing
Marika Asgari, Andy Taylor, Benjamin Joachimi +1
We investigate the use of estimators of weak lensing power spectra based on a flat-sky implementation of the Pseudo-Cl (PCl) technique, where the masked shear field is transformed…
Optically-passive spirals: The missing link in gradual star formation suppression upon cluster infall
Christian Wolf, Alfonso Aragón-Salamanca, Michael Balogh +22
Galaxies migrate from the blue cloud to the red sequence when their star formation is quenched. Here, we report on galaxies quenched by environmental effects and not by mergers or…
Mitigating baryon feedback bias in cosmic shear through a theoretical error covariance in the matter power spectrum
Alessandro Maraio, Alex Hall, Andy Taylor
Forthcoming cosmic shear surveys will make precise measurements of the matter density field down to very small scales, scales which are dominated by baryon feedback. The modelling…
Reconstructing PSCz with a Generalised PIZA
Helen Valentine, Will Saunders, Andy Taylor
We present a generalized version of the Path Interchange Zel'dovich Approximation (PIZA), for use with realistic galaxy redshift surveys. PIZA is a linear particle-based Lagrangian…
Cosmology and Fundamental Physics with the Euclid Satellite
Luca Amendola, Stephen Appleby, Anastasios Avgoustidis +69
Euclid is a European Space Agency medium class mission selected for launch in 2020 within the Cosmic Vision 2015 2025 program. The main goal of Euclid is to understand the origin o…
Density and Velocity Fields from the PSCz Survey
Will Saunders, Enzo Branchini, Luis Teodoro +17
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…
Space-quality data from balloon-borne telescopes: the High Altitude Lensing Observatory (HALO)
Jason Rhodes, Benjamin Dobke, Jeffrey Booth +36
We present a method for attaining sub-arcsecond pointing stability during sub- orbital balloon flights, as designed for in the High Altitude Lensing Observatory (HALO) concept. The…
Redshift-space distortions around voids
Yan-Chuan Cai, Andy Taylor, John A. Peacock +1
We have derived estimators for the linear growth rate of density fluctuations using the cross-correlation function of voids and haloes in redshift space, both directly and in Fouri…
Cross-correlation Tomography: Measuring Dark Energy Evolution with Weak Lensing
Bhuvnesh Jain, Andy Taylor
A cross-correlation technique of lensing tomography is presented to measure the evolution of dark energy in the universe. The variation of the weak lensing shear with redshift arou…
Flexion measurement in simulations of Hubble Space Telescope data
Barnaby Rowe, David Bacon, Richard Massey +5
We present a simulation analysis of weak gravitational lensing flexion and shear measurement using shapelet decomposition, and identify differences between flexion and shear measur…
Karhunen-Loeve eigenvalue problems in cosmology: how should we tackle large data sets?
Max Tegmark, Andy Taylor, Alan Heavens
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 eigenva…
The non-gravitational interactions of dark matter in colliding galaxy clusters
David Harvey, Richard Massey, Thomas Kitching +2
Collisions between galaxy clusters provide a test of the non-gravitational forces acting on dark matter. Dark matter's lack of deceleration in the `bullet cluster collision' constr…
Validation of PSF Models for HST and Other Space-Based Observations
Bryan R. Gillis, Tim Schrabback, Ole Marggraf +4
Forthcoming space-based observations will require high-quality point-spread function (PSF) models for weak gravitational lensing measurements. One approach to generating these mode…
Non-Gaussian likelihood of weak lensing power spectra
Alex Hall, Andy Taylor
The power spectrum of weak lensing fluctuations has a non-Gaussian distribution due to its quadratic nature. On small scales the Central Limit Theorem acts to Gaussianize this dist…
Towards determining the neutrino mass hierarchy: weak lensing and galaxy clustering forecasts with baryons and intrinsic alignments
David Copeland, Andy Taylor, Alex Hall
The capacity of Stage IV lensing surveys to measure the neutrino mass sum and differentiate between the normal and inverted mass hierarchies depends on the impact of nuisance param…
Reconstructing Horndeski models from the effective field theory of dark energy
Joe Kennedy, Lucas Lombriser, Andy Taylor
Studying the effects of dark energy and modified gravity on cosmological scales has led to a great number of physical models being developed. The effective field theory (EFT) of co…
On the cross-section of Dark Matter using substructure infall into galaxy clusters
David Harvey, Eric Tittley, Richard Massey +6
We develop a statistical method to measure the interaction cross-section of Dark Matter, exploiting the continuous minor merger events in which small substructures fall into galaxy…
Cosmology and fundamental physics with the Euclid satellite
Luca Amendola, Stephen Appleby, David Bacon +60
Euclid is a European Space Agency medium class mission selected for launch in 2019 within the Cosmic Vision 2015-2025 programme. The main goal of Euclid is to understand the origin…
Intrinsic alignments in the cross-correlation of cosmic shear and CMB weak lensing
Alex Hall, Andy Taylor
We demonstrate that the intrinsic alignment of galaxies with large-scale tidal fields sources an extra contribution to the recently-detected cross-correlation of galaxy shear and w…
Hybrid Quintessential Inflation
Mar Bastero-Gil, Arjun Berera, Brendan M. Jackson +1
A model is presented in which a single scalar field is responsible for both primordial inflation at early times and then dark energy at late times. This field is coupled to a secon…
Reconstructing Horndeski theories from phenomenological modified gravity and dark energy models on cosmological scales
Joe Kennedy, Lucas Lombriser, Andy Taylor
Recently we have derived a set of mapping relations that enables the reconstruction of the family of Horndeski scalar-tensor theories which reproduce the background dynamics and li…