MultiDarkLens Simulations: weak lensing light-cones and data base presentation

Giocoli, Carlo; Jullo, Eric; Metcalf, R. Benton; Torre, S. de la; Yepes, Gustavo; Prada, Francisco; Comparat, Johan; Gottlöber, Stefan; Kyplin, Anatoly; Kneib, Jean-Paul; Petkova, Margarita; Shan, Huanyuan; Tessore, Nicolas

doi:10.1093/mnras/stw1336

Cited by 32 publications

(33 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result corroborates past similar conclusions in the literature (e.g. Jain et al 2000;Hilbert et al 2009;Giocoli et al 2016;Fabbian et al 2019).…”

Section: Born Approximationsupporting

confidence: 94%

The accuracy of weak lensing simulations

Hilbert

Barreira

Fabbian

et al. 2020

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We investigate the accuracy of weak lensing simulations by comparing the results of five independently developed lensing simulation codes run on the same input N -body simulation. Our comparison focuses on the lensing convergence maps produced by the codes, and in particular on the corresponding PDFs, power spectra and peak counts. We find that the convergence power spectra of the lensing codes agree to 2% out to scales ≈ 4000. For lensing peak counts, the agreement is better than 5% for peaks with signal-to-noise 6. We also discuss the systematic errors due to the Born approximation, line-of-sight discretization, particle noise and smoothing. The lensing codes tested deal in markedly different ways with these effects, but they nonetheless display a satisfactory level of agreement. Our results thus suggest that systematic errors due to the operation of existing lensing codes should be small. Moreover their impact on the convergence power spectra for a lensing simulation can be predicted given its numerical details, which may then serve as a validation test.

show abstract

“…This result corroborates past similar conclusions in the literature (e.g. Jain et al 2000;Hilbert et al 2009;Giocoli et al 2016;Fabbian et al 2019).…”

Section: Born Approximationsupporting

confidence: 94%

The accuracy of weak lensing simulations

Hilbert

Barreira

Fabbian

et al. 2020

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

show abstract

“…A possible examples is the recently released Multidark weak lensing lightcone [54]. This will offer the possibility to not only extend the redshift range, but also adjust the source redshift distribution thus allowing to explore the impact of this quantity on the validity of our linear calibration relation.…”

Section: Discussionmentioning

confidence: 99%

Increasing the lensing figure of merit through higher order convergence moments

et al. 2018

View full text Add to dashboard Cite

The unprecedented quality, the increased dataset, and the wide area of ongoing and near future weak lensing surveys allows to move beyond the standard two points statistics thus making worthwhile to investigate higher order probes. As an interesting step towards this direction, we expolore the use of higher order moments (HOM) of the convergence field as a way to increase the lensing Figure of Merit (FoM). To this end, we rely on simulated convergence to first show that HOM can be measured and calibrated so that it is indeed possible to predict them for a given cosmological model provided suitable nuisance parameters are introduced and then marginalized over. We then forecast the accuracy on cosmological parameters from the use of HOM alone and in combination with standard shear power spectra tomography. It turns out that HOM allow to break some common degeneracies thus significantly boosting the overall FoM. We also qualitatively discuss possible systematics and how they can be dealt with.PACS numbers: 98.80.Es, 95.36.+x

show abstract

“…Since gravitational lensing is sensitive to the projected matter density distribution along the line-of-sight, we projected onto each lens plane all particles between two defined comoving distances from the observer, and in the simulations with massive neutrinos we consistently also accounted for this component, as well as for the proper Hubble function and the comoving distance calculation. As was done by Petri et al (2016Petri et al ( , 2017; Giocoli et al (2017Giocoli et al ( , 2018b; Castro et al (2018), we constructed the convergence maps by weighting the lens planes by the lensing kernel and assuming the Born approximation (Schäfer et al 2012;Giocoli et al 2016;Castro et al 2018), which represents an excellent estimation for weak cosmic lensing down to very small scales ( ≥ 10 4 ). From Σ l we can write down the convergence map κ at Article number, page 4 of 19 A.…”

Section: Map Makingmentioning

confidence: 99%

Breaking degeneracies in modified gravity with higher (than 2nd) order weak-lensing statistics

Peel

Pettorino

Giocoli

et al. 2018

A&A

Self Cite

View full text Add to dashboard Cite

General relativity (GR) has been well tested up to solar system scales, but it is much less certain that standard gravity remains an accurate description on the largest, that is, cosmological, scales. Many extensions to GR have been studied that are not yet ruled out by the data, including by that of the recent direct gravitational wave detections. Degeneracies among the standard model (ΛCDM) and modified gravity (MG) models, as well as among different MG parameters, must be addressed in order to best exploit information from current and future surveys and to unveil the nature of dark energy. We propose various higher-order statistics in the weaklensing signal as a new set of observables able to break degeneracies between massive neutrinos and MG parameters. We have tested our methodology on so-called f (R) models, which constitute a class of viable models that can explain the accelerated universal expansion by a modification of the fundamental gravitational interaction. We have explored a range of these models that still fit current observations at the background and linear level, and we show using numerical simulations that certain models which include massive neutrinos are able to mimic ΛCDM in terms of the 3D power spectrum of matter density fluctuations. We find that depending on the redshift and angular scale of observation, non-Gaussian information accessed by higher-order weak-lensing statistics can be used to break the degeneracy between f (R) models and ΛCDM. In particular, peak counts computed in aperture mass maps outperform thirdand fourth-order moments.

show abstract

MultiDarkLens Simulations: weak lensing light-cones and data base presentation

Cited by 32 publications

References 39 publications

The accuracy of weak lensing simulations

The accuracy of weak lensing simulations

Increasing the lensing figure of merit through higher order convergence moments

Breaking degeneracies in modified gravity with higher (than 2nd) order weak-lensing statistics

Contact Info

Product

Resources

About