A5045169246- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Radio Astronomy Observations and Technology
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Scientific Research and Discoveries
- Computational Physics and Python Applications
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Particle physics theoretical and experimental studies
- Remote Sensing in Agriculture
- Statistical and numerical algorithms
- Superconducting and THz Device Technology
- Advanced Vision and Imaging
- Climate variability and models
- GNSS positioning and interference
- Geophysics and Gravity Measurements
- Advanced Physical and Chemical Molecular Interactions
- Spectroscopy and Chemometric Analyses
- Relativity and Gravitational Theory
- Advanced Thermodynamics and Statistical Mechanics
- Optical measurement and interference techniques
- Stellar, planetary, and galactic studies
University of Edinburgh
2022-2025
Royal Observatory
2022-2025
University of the Western Cape
2019-2025
UK Astronomy Technology Centre
2023-2024
Newcastle University
2023
Queen Mary University of London
2017-2022
University of Portsmouth
2015-2020
University of Geneva
2019
Astronomy and Space
2017
National Institute for Space Research
2016
Abstract We present a detailed overview of the cosmological surveys that we aim to carry out with Phase 1 Square Kilometre Array (SKA1) and science they will enable. highlight three main surveys: medium-deep continuum weak lensing low-redshift spectroscopic HI galaxy survey over 5 000 deg 2 ; wide deep intensity mapping (IM) 20 from $z = 0.35$ 3; deep, high-redshift IM 100 3$ 6. Taken together, these achieve an array important scientific goals: measuring equation state dark energy \sim...
The Euclid space telescope will measure the shapes and redshifts of galaxies to reconstruct expansion history Universe growth cosmic structures. Estimation expected performance experiment, in terms predicted constraints on cosmological parameters, has so far relied different methodologies numerical implementations, developed for observational probes their combination. In this paper we present validated forecasts, that combine both theoretical expertise probes. This is presented provide...
We discuss the detection of large scale HI intensity fluctuations using a single dish approach with ultimate objective measuring Baryonic Acoustic Oscillations and constraining properties dark energy. present 3D power spectra, 2D angular spectra for individual redshift slices, also line-of-sight computed S^3 simulated catalogue which is based on Millennium Simulation. consider optimal instrument design survey strategies observation at low high fixed sensitivity. For corresponding to an...
We study a coupled quintessence model with pure momentum exchange and present the effects of such an interaction on Cosmic Microwave Background (CMB) matter power spectrum. For wide range negative values coupling parameter $\beta$ structure growth is suppressed can reconcile tension between observations inferred from cluster counts. find that this as good $\Lambda$CDM for CMB baryon acoustic oscillation (BAO) data, while addition data makes strongly preferred, improving best-fit...
Abstract The detection of the accelerated expansion Universe has been one major breakthroughs in modern cosmology. Several cosmological probes (Cosmic Microwave Background, Supernovae Type Ia, Baryon Acoustic Oscillations) have studied depth to better understand nature mechanism driving this acceleration, and they are being currently pushed their limits, obtaining remarkable constraints that allowed us shape standard model. In parallel that, however, percent precision achieved recently...
Abstract We analyse the BOSS DR12 multipoles of galaxy power spectrum jointly with measurements BAO scale for three different models dark energy. use recent performed a windowless estimator, and an independent fast pipeline based on EFTofLSS modelling implemented via FAST-PT algorithm to compute integrals redshift-space loop corrections. accelerate our analysis further by using bacco linear emulator instead Boltzmann solver. perform two sets analyses: one including 3 σ Planck priors A s n ,...
HI intensity mapping (IM) is a novel technique capable of the large-scale structure Universe in three dimensions and delivering exquisite constraints on cosmology, by using as biased tracer dark matter density field.This achieved measuring redshifted 21cm line over sky range redshifts without requirement to resolve individual galaxies.In this chapter, we investigate potential SKA1 deliver maps broad frequencies substantial fraction sky.By pinning down baryon acoustic oscillation redshift...
We present three distinct types of models dark energy in the form a scalar field which is explicitly coupled to matter. Our construction draws from pull-back formalism for fluids and generalizes fluid action involve couplings field. investigate cosmology each class model both at background linearly perturbed level. choose potential specific coupling function we compute cosmic microwave matter power spectra.
Abstract The Square Kilometre Array (SKA) is a planned large radio interferometer designed to operate over wide range of frequencies, and with an order magnitude greater sensitivity survey speed than any current telescope. SKA will address many important topics in astronomy, ranging from planet formation distant galaxies. However, this work, we consider the perspective as facility for studying physics. We review four areas which expected make major contributions our understanding fundamental...
We present the most general parametrisation of models dark energy in form a scalar field which is explicitly coupled to matter. follow and extend Parameterized Post-Friedmannian approach, previously applied modified gravity theories, order include interacting energy. demonstrate its use through number worked examples show how initially large parameter space free functions can be significantly reduced constrained only few non-zero coefficients. This paves way for model-independent approach...
We present the joint analysis of Neutral Hydrogen (HI) Intensity Mapping observations with three galaxy samples: Luminous Red Galaxy (LRG) and Emission Line (ELG) samples from eBOSS survey, WiggleZ Dark Energy Survey sample. The HI intensity maps are Green Bank Telescope redshifted 21cm emission on 100deg2 covering redshift range $0.6<z<1.0$. process data by separating removing foregrounds FastICA, construct a transfer function to correct for effects foreground removal signal....
While most purpose-built 21cm intensity mapping experiments are close-packed interferometer arrays, general-purpose dish arrays should also be capable of measuring the cosmological signal. This can achieved efficiently if array is used as a collection scanning autocorrelation dishes rather than an interferometer. As first step towards demonstrating feasibility this observing strategy, we show that able to successfully calibrate dual-polarisation data from 64 MeerKAT in L-band (856-1712 MHz,...
We present a detection of correlated clustering between MeerKAT radio intensity maps and galaxies from the WiggleZ Dark Energy Survey. find $7.7\sigma$ cross-correlation power spectrum, amplitude which is proportional to product HI density fraction ($\Omega_{\rm HI}$), bias ($b_{\rm HI}$) coefficient ($r$). therefore obtain constraint $\Omega_{\rm HI} b_{\rm r\,{=}\,[0.86\,{\pm}\,0.10\,({\rm stat})\,{\pm}\,0.12\,({\rm sys})]\,{\times}\,10^{-3}$, at an effective scale $k_{\rm...
We discuss the ground-breaking science that will be possible with a wide area survey, using MeerKAT telescope, known as MeerKLASS (MeerKAT Large Area Synoptic Survey). The current specifications of make it great fit for applications require large survey speeds but not necessarily high angular resolutions. In particular, cosmology, over $\sim 4,000 \, {\rm deg}^2$ 4,000$ hours potentially provide first ever measurements baryon acoustic oscillations 21cm intensity mapping technique, enough...
We forecast constraints on neutral hydrogen (HI) and cosmological parameters using near-term intensity mapping surveys with instruments such as BINGO, MeerKAT, the SKA, Stage III IV optical galaxy surveys. If foregrounds systematic effects can be controlled - a problem which becomes much easier in cross-correlation these will provide exquisite measurements of HI density bias, well growth structure, angular diameter distance, Hubble rate, over wide range redshift. also investigate possibility...
The combination and cross-correlation of the upcoming $Euclid$ data with cosmic microwave background (CMB) measurements is a source great expectation since it will provide largest lever arm epochs, ranging from recombination to structure formation across entire past light cone. In this work, we present forecasts for joint analysis CMB on cosmological parameters standard model some its extensions. This work expands complements recently published based $Euclid$-specific probes, namely galaxy...
The success of HI intensity mapping is largely dependent on how well 21cm foreground contamination can be controlled. In order to progress our understanding further, we present a range simulated data from four different $\sim3000$\,deg$^2$ sky regions, with and without effects polarization leakage. Combining these underlying cosmological simulations creates single-dish test cases that require treatments. This allows us conduct the most generalized study date into foregrounds their cleaning...
Neutral Hydrogen Intensity Mapping (HI IM) surveys will be a powerful new probe of cosmology. However, strong astrophysical foregrounds contaminate the signal and their coupling with instrumental systematics further increases data cleaning complexity. In this work, we simulate realistic single-dish HI IM survey $5000$~deg$^2$ patch in $950 - 1400$ MHz range, both MID telescope SKA Observatory (SKAO) MeerKAT, its precursor. We include state-of-the-art simulations explore different foreground...
We embed linear and nonlinear parametrisations of beyond standard cosmological physics in the halo model reaction framework, providing a model-independent prescription for matter power spectrum. As an application, we focus on Horndeski theories, using Effective Field Theory Dark Energy (EFTofDE) to parameterise quasi-nonlinear perturbations. In regime investigate both parameterised-post Friedmannian (nPPF) approach as well physically motivated approximate phenomenological based error...
Blind cleaning methods are currently the preferred strategy for handling foreground contamination in single-dish HI intensity mapping surveys. Despite increasing sophistication of blind techniques, some signal loss will be inevitable across all scales. Constructing a corrective transfer function using mock injection into contaminated data has been practice relied on experiments. However, assessing whether this approach is viable future surveys where precision cosmology aim, remains...
Context. The Euclid space satellite mission will measure the large-scale clustering of galaxies at an unprecedented precision, providing a unique probe modifications to ΛCDM model. Aims. We investigated approximations needed efficiently predict matter and dark halos in context modified gravity exotic energy scenarios. examined normal branch Dvali–Gabadadze–Porrati model, Hu–Sawicki f ( R ) slowly evolving interacting massive neutrinos. For each, we tested for perturbative kernel...
Models in which scalar field dark energy interacts with matter via a pure momentum coupling have previously been found to potentially ease the structure formation tension between early- and late-universe observations. In this article we explore physical mechanism underlying feature. We argue analytically that perturbation growth equations imply suppression of growth, illustrating our discussion numerical calculations. Then generalise studied quadratic more general power law case, also...
Interacting dark energy models have been suggested as alternatives to the standard cosmological model, $\Lambda$CDM. We focus on a phenomenologically interesting class of scattering that is characterised by pure momentum exchange between and matter. This model extends parameter space with respect $\Lambda$CDM two parameters, $w$ $A$, which define equation state strength coupling matter, respectively. In order test non-standard cosmologies Stage-IV galaxy clustering surveys, it crucial mildly...