papers

Publications (49)

astro-ph.CO2025

The Atacama Cosmology Telescope: DR6 Power Spectra, Likelihoods and CDM Parameters

Thibaut Louis, Adrien La Posta, Zachary Atkins +165

We present power spectra of the cosmic microwave background (CMB) anisotropy in temperature and polarization, measured from the Data Release 6 maps made from Atacama Cosmology Tele…

astro-ph.CO2021

Constraining Scalar-Tensor Modified Gravity with Gravitational Waves and Large Scale Structure Surveys

Tessa Baker, Ian Harrison

The first multi-messenger gravitational wave event has had a transformative effect on the space of modified gravity models. In this paper we study the enhanced tests of gravity tha…

astro-ph.CO2024

Cosmology and Source Redshift Distributions from Combining Radio Weak Lensing with CMB Lensing

Alba Kalaja, Ian Harrison, William R Coulton

Measurements of weak gravitational lensing using the cosmic microwave background and the shapes of galaxies have refined our understanding of the late-time history of the Universe.…

astro-ph.CO2026

Propagating data-driven galaxy redshift distribution uncertainties in 32-pt analyses

Jaime Ruiz-Zapatero, Qianjun Hang, Yun-Hao Zhang +7

Uncertainties in the radial distribution of galaxies, , are one of the major contributions to the error budget of early Stage-IV galaxy survey analy…

astro-ph.CO2024

The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters

Mathew S. Madhavacheril, Frank J. Qu, Blake D. Sherwin +156

We present cosmological constraints from a gravitational lensing mass map covering 9400 sq. deg. reconstructed from CMB measurements made by the Atacama Cosmology Telescope (ACT) f…

astro-ph.CO2020

Cosmology Intertwined II: The Hubble Constant Tension

Eleonora Di Valentino, Luis A. Anchordoqui, Ozgur Akarsu +90

The current cosmological probes have provided a fantastic confirmation of the standard Cold Dark Matter cosmological model, that has been constrained with unprecedented accura…

astro-ph.CO2016

SKA Weak Lensing III: Added Value of Multi-Wavelength Synergies for the Mitigation of Systematics

Stefano Camera, Ian Harrison, Anna Bonaldi +1

In this third paper of a series on radio weak lensing for cosmology with the Square Kilometre Array, we scrutinise synergies between cosmic shear measurements in the radio and opti…

astro-ph.CO2025

The Atacama Cosmology Telescope: DR6 Maps

Sigurd Naess, Yilun Guan, Adriaan J. Duivenvoorden +163

We present Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) maps of the Cosmic Microwave Background temperature and polarization anisotropy at arcminute resolution over three…

astro-ph.CO2017

Redshifts for galaxies in radio continuum surveys from Bayesian model fitting of HI 21-cm lines

Ian Harrison, Michelle Lochner, Michael L. Brown

We introduce a new Bayesian HI spectral line fitting technique capable of obtaining spectroscopic redshifts for millions of galaxies in radio surveys with the Square Kilometere Arr…

astro-ph.CO2017

A Consistent Approach to Falsifying Lambda-CDM with Rare Galaxy Clusters

Ian Harrison, Shaun Hotchkiss

We consider methods with which to answer the question "is any observed galaxy cluster too unusual for Lambda-CDM?" After emphasising that many previous attempts to answer this ques…

astro-ph.GA2016

Radio-Optical Galaxy Shape Correlations in the COSMOS Field

Ben Tunbridge, Ian Harrison, Michael L. Brown

We investigate the correlations in galaxy shapes between optical and radio wavelengths using archival observations of the COSMOS field. Cross-correlation studies between different…

astro-ph.CO2018

Cosmology with Phase 1 of the Square Kilometre Array; Red Book 2018: Technical specifications and performance forecasts

Square Kilometre Array Cosmology Science Working Group, David J. Bacon, Richard A. Battye +44

We present a detailed overview of the cosmological surveys that will be carried out with Phase 1 of the Square Kilometre Array (SKA1), and the science that they will enable. We hig…

astro-ph.CO2026

Cosmology from Nx2pt Analyses of SKAO Wide-Area Surveys

Ian Harrison, Ziad Sakr, Giulia Piccirilli +7

The paper forecasts how combined analyses of galaxy clustering, weak lensing, galaxy‑galaxy lensing and 21 cm intensity mapping from SKA‑Mid surveys can measure ΛCDM parameters to…

#large-scale structure#21cm intensity mapping#galaxy clustering#weak lensing
astro-ph.CO2026

Brightest Cluster Galaxy ellipticity as proxy for halo shape: Orientation bias, assembly bias, and potential selection effects in SZ-selected clusters

Radhakrishnan Srinivasan, Tae-hyeon Shin, Anja von der Linden +93

The orientation of triaxial galaxy clusters with respect to the line-of-sight is expected to be one of the prime sources of scatter and potential bias in optical observables (e.g.,…

cond-mat.mtrl-sci2024

Large Bandgap Observed on the Surfaces of EuZn2As2 Single Crystals

Dejia Kong, Siavash Karbasizadeh, Ganesh Narasimha +7

EuM2As2 (M = Zn, Cd, In, Sn etc.) is an excellent material system for studying topological properties, which can be easily tuned by magnetism involved. Theoretical calculations pre…

astro-ph.IM2021

SkyPy: A package for modelling the Universe

Adam Amara, Lucia F. de la Bella, Simon Birrer +18

SkyPy is an open-source Python package for simulating the astrophysical sky. It comprises a library of physical and empirical models across a range of observables and a command-lin…

astro-ph.CO2015

Weak Lensing Simulations for the SKA

Prina Patel, Ian Harrison, Sphesihle Makhathini +6

Weak gravitational lensing measurements are traditionally made at optical wavelengths where many highly resolved galaxy images are readily available. However, the Square Kilometre…

astro-ph.IM2019

LISA Pathfinder

Michele Armano, Heather Audley, Jonathon Baird +75

Since the 2017 Nobel Prize in Physics was awarded for the observation of gravitational waves, it is fair to say that the epoch of gravitational wave astronomy (GWs) has begun. Howe…

astro-ph.CO2013

Testing Cosmology with Extreme Galaxy Clusters

Ian Harrison, Peter Coles

Motivated by recent suggestions that a number of observed galaxy clusters have masses which are too high for their given redshift to occur naturally in a standard model cosmology,…

astro-ph.CO2020

Cosmology Intertwined I: Perspectives for the Next Decade

Eleonora Di Valentino, Luis A. Anchordoqui, Ozgur Akarsu +89

The standard Cold Dark Matter cosmological model provides an amazing description of a wide range of astrophysical and astronomical data. However, there are a few big open ques…

astro-ph.CO2018

Weak gravitational lensing with CO galaxies

Philip Bull, Ian Harrison, Eric Huff

Optical weak lensing surveys have become a powerful tool for precision cosmology, but remain subject to systematic effects that can severely bias cosmological parameter estimates i…

astro-ph.GA2020

SuperCLASS -- I. The Super CLuster Assisted Shear Survey: Project overview and Data Release 1

Richard A. Battye, Michael L. Brown, Caitlin M. Casey +24

The SuperCLuster Assisted Shear Survey (SuperCLASS) is a legacy programme using the e-MERLIN interferometric array. The aim is to observe the sky at L-band (1.4 GHz) to a r.m.s. of…

astro-ph.CO2026

Cosmology from Synergies Between SKAO Surveys and Gravitational Wave Observations

Tessa Baker, Alberto Colombo, Steven Cunnington +11

Both radio surveys and gravitational wave observations have the potential to probe unprecedented volumes in the Universe with systematics independent of existing cosmological probe…

astro-ph.CO2022

Dark Energy Survey Year 3 results: Marginalisation over redshift distribution uncertainties using ranking of discrete realisations

Juan P. Cordero, Ian Harrison, Richard P. Rollins +92

Cosmological information from weak lensing surveys is maximised by dividing source galaxies into tomographic sub-samples for which the redshift distributions are estimated. Uncerta…

astro-ph.GA2020

SuperCLASS -- II: Photometric Redshifts and Characteristics of Spatially-Resolved Jy Radio Sources

Sinclaire M. Manning, Caitlin M. Casey, Chao-Ling Hung +12

We present optical and near-infrared imaging covering a 1.53 deg region in the Super-Cluster Assisted Shear Survey (SuperCLASS) field, which aims to make the first robust…

astro-ph.CO2026

Overview: Cosmology with the SKAO

Marta Spinelli, Ian Harrison, Richard A. Battye +5

The SKA telescopes will revolutionise our ability to do cosmology at radio wavelengths, via both their own data and in synergy with other wavelengths. SKAO will be the first instru…

astro-ph.CO2026

Radio sirens: inferring with binary black holes and neutral hydrogen in the era of the Einstein Telescope and the SKA Observatory

Ulyana Dupletsa, Simone Mastrogiovanni, Marta Spinelli +11

A new synergy between gravitational waves (GWs) and the study of the large-scale structure of the Universe is now emerging. Along this line of research, we combine simulated observ…

astro-ph.IM2024

The PLATO Mission

Heike Rauer, Conny Aerts, Juan Cabrera +842

PLATO (PLAnetary Transits and Oscillations of stars) is ESA's M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large numb…

astro-ph.GA2022

Extreme Value Statistics of the Halo and Stellar Mass Distributions at High Redshift: are JWST Results in Tension with ΛCDM?

Christopher C. Lovell, Ian Harrison, Yuichi Harikane +2

The distribution of dark matter halo masses can be accurately predicted in the CDM cosmology. The presence of a single massive halo or galaxy at a particular redshift, assuming…

astro-ph.CO2025

The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth

Frank J. Qu, Blake D. Sherwin, Mathew S. Madhavacheril +155

We present new measurements of cosmic microwave background (CMB) lensing over sq. deg. of the sky. These lensing measurements are derived from the Atacama Cosmology Telescop…

astro-ph.CO2020

SuperCLASS -- III. Weak lensing from radio and optical observations in Data Release 1

Ian Harrison, Michael L. Brown, Ben Tunbridge +17

We describe the first results on weak gravitational lensing from the SuperCLASS survey: the first survey specifically designed to measure the weak lensing effect in radio-wavelengt…

astro-ph.IM2015

SKA Engineering Change Proposal: Gridded Visibilities to Enable Precision Cosmology with Radio Weak Lensing

Ian Harrison, Michael L. Brown

This document was submitted as supporting material to an Engineering Change Proposal (ECP) for the Square Kilometre Array (SKA). This ECP requests gridded visibilities as an extra…

astro-ph.CO2011

Exact Extreme Value Statistics and the Halo Mass Function

Ian Harrison, Peter Coles

Motivated by observations that suggest the presence of extremely massive clusters at uncomfortably high redshifts for the standard cosmological model to explain, we develop a theor…

astro-ph.CO2022

Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies

Elcio Abdalla, Guillermo Franco Abellán, Amin Aboubrahim +200

In this paper we will list a few important goals that need to be addressed in the next decade, also taking into account the current discordances between the different cosmological…

astro-ph.GA2022

Dwarf AGNs from Optical Variability for the Origins of Seeds (DAVOS): Insights from the Dark Energy Survey Deep Fields

Colin J. Burke, Xin Liu, Yue Shen +69

We present a sample of 706, active galactic nuclei (AGNs) selected from optical photometric variability in three of the Dark Energy Survey (DES) deep fields (E2, C3, and…

astro-ph.CO2020

Cosmology Intertwined IV: The Age of the Universe and its Curvature

Eleonora Di Valentino, Luis A. Anchordoqui, Ozgur Akarsu +88

A precise measurement of the curvature of the Universe is of primeval importance for cosmology since it could not only confirm the paradigm of primordial inflation but also help in…

astro-ph.CO2020

Source Distributions of Cosmic Shear Surveys in Efficiency Space

Nicolas Tessore, Ian Harrison

We show that the lensing efficiency of cosmic shear generically has a simple shape, even in the case of a tomographic survey with badly behaved photometric redshifts. We argue that…

astro-ph.CO2019

Radio-Optical Galaxy Shape and Shear Correlations in the COSMOS Field using 3 GHz VLA Observations

Tom Hillier, Michael L. Brown, Ian Harrison +1

We present a weak lensing analysis of the 3 GHz VLA radio survey of the COSMOS field, which we correlate with overlapping HST-ACS optical observations using both intrinsic galaxy s…

astro-ph.GA2018

The Tiered Radio Extragalactic Continuum Simulation (T-RECS)

Anna Bonaldi, Matteo Bonato, Vincenzo Galluzzi +5

We present the Tiered Radio Extragalactic Continuum Simulation (T-RECS): a new simulation of the radio sky in continuum, over the 150 MHz-20 GHz range. T-RECS models two main popul…

astro-ph.IM2026

Advancing Astrophysics with the SKA II

Anna Bonaldi, Tyler L. Bourke, Philippa Hartley +45

Advancing Astrophysics with the SKA II (AASKAII), written by our science community, outlines the transformative scientific advances that will be enabled by the SKA telescopes. In t…

astro-ph.CO2025

The Atacama Cosmology Telescope: DR6 Gravitational Lensing and SDSS BOSS cross-correlation measurement and constraints on gravity with the statistic

Lukas Wenzl, Rui An, Nick Battaglia +24

We derive new constraints on the statistic as a test of gravity, combining the CMB lensing map estimated from Data Release 6 (DR6) of the Atacama Cosmology Telescope with SDS…

astro-ph.CO2020

Cosmology Intertwined III: and

Eleonora Di Valentino, Luis A. Anchordoqui, Ozgur Akarsu +89

The standard Cold Dark Matter cosmological model provides a wonderful fit to current cosmological data, but a few tensions and anomalies became statistically significant with…

astro-ph.CO2016

SKA Weak Lensing II: Simulated Performance and Survey Design Considerations

Anna Bonaldi, Ian Harrison, Stefano Camera +1

We construct a pipeline for simulating weak lensing cosmology surveys with the Square Kilometre Array (SKA), taking as inputs telescope sensitivity curves; correlated source flux,…

astro-ph.CO2025

The Atacama Cosmology Telescope: DR6 Constraints on Extended Cosmological Models

Erminia Calabrese, J. Colin Hill, Hidde T. Jense +169

We use new cosmic microwave background (CMB) primary temperature and polarization anisotropy measurements from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) to test fo…

astro-ph.CO2026

Weak Lensing with SKAO: Cosmic Shear Cosmology

Ian Harrison, Roberto Ingrao, Stefano Camera +4

We discuss the power of weak gravitational lensing surveys with the SKAO in constraining cosmological parameters and the properties of radio star-forming galaxy samples. As well as…

astro-ph.GA2026

Weak Lensing with the SKAO: Radio Shear Measurement

Priyamvad Tripathi, Marzia Rivi, Simon Prunet +2

Cosmic shear measurements have traditionally been dominated by optical surveys, which offer higher resolution, better sensitivity, higher galaxy number density, and wider area cove…

astro-ph.CO2018

HI Intensity Mapping for Clustering-Based Redshift Estimation

Steven Cunnington, Ian Harrison, Alkistis Pourtsidou +1

Precision cosmology requires accurate galaxy redshifts, but next generation optical surveys will observe unprecedented numbers of resolved galaxies, placing strain on the amount of…

astro-ph.IM2018

LISA Pathfinder Platform Stability and Drag-free Performance

Michele Armano, Heather Audley, Jonathon Baird +75

The science operations of the LISA Pathfinder mission has demonstrated the feasibility of sub-femto-g free-fall of macroscopic test masses necessary to build a LISA-like gravitatio…

astro-ph.CO2016

SKA Weak Lensing I: Cosmological Forecasts and the Power of Radio-Optical Cross-Correlations

Ian Harrison, Stefano Camera, Joe Zuntz +1

We construct forecasts for cosmological parameter constraints from weak gravitational lensing surveys involving the Square Kilometre Array (SKA). Considering matter content, dark e…