A5069989486- Galaxies: Formation, Evolution, Phenomena
- Statistical and numerical algorithms
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Radio Astronomy Observations and Technology
- Gaussian Processes and Bayesian Inference
- demographic modeling and climate adaptation
- Hydrology and Drought Analysis
- Gamma-ray bursts and supernovae
- Particle physics theoretical and experimental studies
- Stellar, planetary, and galactic studies
- Historical Astronomy and Related Studies
- Biblical Studies and Interpretation
- Astrophysics and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Neutrino Physics Research
- Scientific Research and Discoveries
- Adaptive optics and wavefront sensing
- Dark Matter and Cosmic Phenomena
- Satellite Image Processing and Photogrammetry
- Historical and Architectural Studies
University of Bonn
2021-2024
University of Sussex
2020-2022
University of Pennsylvania
2022
Recent cosmic shear studies have shown that higher-order statistics (HOS) developed by independent teams now outperform standard two-point estimators in terms of statistical precision thanks to their sensitivity the non-Gaussian features large-scale structure. The aim Higher-Order Weak Lensing Statistics (HOWLS) project is assess, compare, and combine constraining power ten different HOS on a common set $Euclid$-like mocks, derived from N-body simulations. In this first paper HOWLS series,...
Model uncertainties in the nonlinear structure growth limit current probes of cosmological parameters. To shed more light on physics scales, we reconstruct finely binned three-dimensional power-spectrum from lensing data Kilo-Degree Survey (KiDS), relying solely background cosmology, source redshift distributions, and intrinsic alignment (IA) amplitude sources (and their uncertainties). The adopted Tikhonov regularisation stabilises deprojection, enabling a Bayesian reconstruction separate...
Model uncertainties in the non-linear structure growth limit current probes of cosmological parameters. To shed more light on physics scales, we reconstructed finely binned three-dimensional power-spectrum from lensing data Kilo-Degree Survey (KiDS), relying solely background cosmology, source redshift distributions, and intrinsic alignment (IA) amplitude sources (and their uncertainties). The adopted Tikhonov regularisation stabilises deprojection, enabling a Bayesian reconstruction...
This paper performs the first cosmological parameter analysis of KiDS-1000 data with second- and third-order shear statistics. work builds on a series papers that describe roadmap to We derive test combined model second-order statistic, namely COSEBIs aperture mass statistics $\langle M_\mathrm{ap}^3\rangle$ in tomographic set-up. validate our pipeline $N$-body simulations mock fourth Kilo Degree survey release. To statistics, we use latest version \textsc{HMcode2020} for power spectrum...
We present the final data release of Kilo-Degree Survey (KiDS-DR5), a public European Southern Observatory (ESO) wide-field imaging survey optimised for weak gravitational lensing studies. combined matched-depth multi-wavelength observations from VLT Telescope and VISTA Kilo-degree INfrared Galaxy (VIKING) to create nine-band optical-to-near-infrared spanning 1347 deg 2 . The median r -band 5 σ limiting magnitude is 24.8 with seeing 0.7″. main footprint includes 4 overlap existing deep...
The power spectrum of the nonlinearly evolved large-scale mass distribution recovers only a minority information available on fluctuation amplitude. We investigate recovery this in 2D "slabs" averaged over $\approx100$~$h^{-1}$Mpc along line sight, as might be obtained from photometric redshift surveys. demonstrate Hamiltonian Monte Carlo (HMC) method to reconstruct non-Gaussian slabs, under assumption that projected field is point-transformed Gaussian random field, Poisson-sampled by...
ABSTRACT We explore an alternative method to the usual shear correlation function approach for estimation of aperture mass statistics in weak-lensing survey data. Our builds on direct estimator method. In this paper, we extend our analysis arbitrary order and multiscale statistics. show that there always exists a linear algorithm retrieve any these generalized from shape catalogues when is adopted. validate through application large number Gaussian mock-lensing surveys where true answer...
Context. Third-order lensing statistics contain a wealth of cosmological information that is not captured by second-order statistics. However, the computational effort it takes to estimate such in forthcoming stage IV surveys prohibitively expensive. Aims. We derive and validate an efficient estimation procedure for three-point correlation function (3PCF) polar fields as weak shear. then use our approach measure shear 3PCF third-order aperture mass on KiDS-1000 survey. Methods constructed...
We explore an alternative method to the usual shear correlation function approach for estimation of aperture mass statistics in weak lensing survey data. Our builds on direct estimator Schneider (1998). In this paper, test and validate methodology, we focus dispersion. After computing signal noise a weighted set measured ellipticites show how can be made into linear order algorithm that enables fast efficient computation. then investigate applicability presence real mask with holes chip...
Cosmological analyses of second-order weak lensing statistics require precise and accurate covariance estimates. These covariances are impacted by two sometimes neglected terms: a negative contribution to the Gaussian due finite survey area, super-sample (SSC), which for power spectrum contains impact Fourier modes larger than window. We show here that these effects connected can be seen as correction terms ‘large-field-approximation’, asymptotic case an infinitely large area. describe...
We introduce OneCovariance, an open-source software designed to accurately compute covariance matrices for arbitrary set of two-point summary statistics across a variety large-scale structure tracers. Utilising the halo model, we estimate statistical properties matter and biased tracer fields, incorporating all Gaussian, non-Gaussian, super-sample terms. The flexible configuration permits user-specific parameters, such as complexity survey geometry, occupation distribution employed define...
We explore the enhanced self-calibration of photometric galaxy redshift distributions, $n(z)$, through combination up to six two-point functions. Our $\rm 3\times2pt$ configuration is comprised shear, spectroscopic clustering, and spectroscopic-photometric galaxy-galaxy lensing (GGL). further include cross-clustering; GGL; auto-clustering, using shear sample as density tracer. perform simulated likelihood forecasts cosmological nuisance parameter constraints for Stage-III- Stage-IV-like...
Third-order lensing statistics contain a wealth of cosmological information that is not captured by second-order statistics. However, the computational effort for estimating such on forthcoming stage IV surveys prohibitively expensive. We derive and validate an efficient estimation procedure three-point correlation function (3PCF) polar fields as weak shear. then use our approach to measure shear 3PCF third-order aperture mass KiDS-1000 survey. construct estimator which builds multipole...
The power spectrum of the nonlinearly evolved large-scale mass distribution recovers only a minority information available on fluctuation amplitude. We investigate recovery this in 2D "slabs" averaged over $\approx100$~$h^{-1}$Mpc along line sight, as might be obtained from photometric redshift surveys. demonstrate Hamiltonian Monte Carlo (HMC) method to reconstruct non-Gaussian slabs, under assumption that projected field is point-transformed Gaussian random field, Poisson-sampled by...
Cosmological analyses of second-order weak lensing statistics require precise and accurate covariance estimates. These covariances are impacted by two sometimes neglected terms: A negative contribution to the Gaussian due finite survey area super-sample (SSC) which for power spectrum contains impact Fourier modes larger than window. We show here that these effects connected can be seen as correction terms "large-field-approximation", asymptotic case an infinitely large area. describe...