Image analysis for cosmology: Shape measurement challenge review &amp; results from the Mapping Dark Matter challenge

Kitching, Thomas D.; Rhodes, Jason; Heymans, Catherine; Massey, Richard; Liu, Q.; Cobzarenco, M.; Cragin, B. L.; Hassaïne, Abdelâali; Kirkby, D.; Lok, E. Jin; Margala, Daniel; Moser, Jürgen; O'Leary, Marion T.; Pires, Ana M.; Yurgenson, Sergey

doi:10.1016/j.ascom.2014.12.004

Cited by 10 publications

(12 citation statements)

References 24 publications

(23 reference statements)

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“…The results from this test for the five-common goodness-of-fit measures provided by Mathematica ® are listed in Table 5. We see that, since the p-values tend to easily exceed the 95% confidence rejection level (i.e., p-values are greater than 0.05) we cannot reject our null hypothesis that Equation (6) describes the available data. …”

Section: Dark Matter Galaxy Cluster Datamentioning

confidence: 79%

“…The data sources, as noted in the table's type column, use different Figure 4 shows the data points from the various utilized mass estimate methods 6 . methods for estimating the mass of the Dark Matter contained in the various clusters.…”

Section: Dark Matter Galaxy Cluster Datamentioning

confidence: 99%

“…The plotted virial mass and radii from identified weak lensing data. 6 The authors are aware of efforts to use lensing of the Cosmic Microwave Background for mapping Dark Matter distributions (https://arxiv.org/pdf/1707.09369.pdf). However, we are awaiting appropriate data to include in future analysis.…”

Section: Dark Matter Galaxy Cluster Datamentioning

confidence: 99%

“…Because Dark Matter has no observed electric charge or opacity (meaning it is transparent to light), the only manifestation of its existence is its gravitational effects, in particular the gravitational bending of light. Extensive reviews of Dark Matter weak lensing techniques are available in the literature (e.g., Kitching [6]). Actual Dark Matter particle searches at the "Conseil Européen pour la Recherche Nucléaire" Large Hadron Collider (CERN LHC) were reviewed by Kahlhoefer [7].…”

Section: Introductionmentioning

confidence: 99%

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Weak Lensing Data and Condensed Neutrino Objects

Morley

Buettner

2017

Universe

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Condensed Neutrino Objects (CNO) are a candidate for the Dark Matter which everyone has been looking for. In this article, from Albert Einstein's original 1911 and 1917 papers, we begin the journey from weak lensing data to neutrino signatures. New research results include an Einasto density profile that fits to a range of candidate degenerate neutrino masses, goodness-of-fit test results for our functional CNO mass/radius relationship which fits to available weak lensing data, and new results based on revised constraints for the CNO that our Local Group of galaxies is embedded in.

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Section: Dark Matter Galaxy Cluster Datamentioning

confidence: 79%

Section: Dark Matter Galaxy Cluster Datamentioning

confidence: 99%

Section: Dark Matter Galaxy Cluster Datamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Weak Lensing Data and Condensed Neutrino Objects

Morley

Buettner

2017

Universe

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“…At each point of the lens field, an average is taken over a number of nearby sources to smooth out the intrinsic ellipticity of the galaxies from that caused by the lens (see e.g. [364,367,368]). Observationally, the field is directly related to the reduced shear, g, as ←→ g ≡ γ/(1 − κ).…”

Section: Cluster Lensing Basicsmentioning

confidence: 99%

Structure Formation in Modified Gravity Cosmologies

Barreira

2016

Springer Theses

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The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source• a link is made to the metadata record in Durham E-Theses• the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. AbstractWe study linear and nonlinear structure formation in cosmologies where the accelerated expansion is driven by modifications to general relativity (GR). We focus on Galileon andNonlocal gravity, which are two classes of models that have been attracting much attention.We derive the linearly perturbed model equations and solve them with suitably modified versions of Einstein-Boltzmann codes. We also derive the perturbed equations keeping the relevant nonlinear terms for small scale structure formation, which we solve using Nbody codes and semi-analytical techniques that were developed for these models. Using CMB, SNIa and BAO data we find strong evidence for nonzero active neutrino masses (Σm ν ≈ 0.6 eV) in all three main branches of covariant Galileon cosmologies, known as the Cubic, Quartic and Quintic models. However, in all branches, the lensing potential does not decay at late times on sub-horizon scales, which contradicts the measured positive sign of the ISW effect, thereby ruling out the Galileon model. The Nonlocal model we study should be able to fit the CMB with similar parameter values as ΛCDM. The N-body simulation results show that the covariant Galileon model admits realistic halo occupation distributions of luminous red galaxies, even for model parameters whose linear growth is noticieably enhanced (σ 8 ≈ 1) relative to ΛCDM. In the Cubic Galileon model the screening mechanism is very efficient on scales 1Mpc, but in the Quartic and Quintic sectors, as well as in the Nonlocal model, we identify potential tensions with Solar System bounds.We illustrate that, despite the direct modifications to the lensing potential in the CubicGalileon and Nonlocal models, cluster masses estimated from lensing remain the same as in GR. The lensing effects produced by cosmic voids found in the simulations of the Cubic Galileon are significanly boosted (≈ 100%) compared to GR, which strongly motivates using voids in tests of gravity. The combination of linear and nonlinear theory results presented here for Galileon and Nonlocal gravity is an example of what it could be done for any serious alternative models to ΛCDM, which will be tested by future experiments.

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Observing Dark Worlds: A crowdsourcing experiment for dark matter mapping

Harvey

Kitching

Noah-Vanhoucke³

et al. 2014

Astronomy and Computing

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We present the results and conclusions from the citizen science competition 'Observing Dark Worlds', where we asked participants to calculate the positions of dark matter halos from 120 catalogues of simulated weak lensing galaxy data, using computational methods. In partnership with Kaggle (http://www.kaggle.com), 357 users participated in the competition which saw 2278 downloads of the data and 3358 submissions. We found that the best algorithms improved on the benchmark code, LENSTOOL by > 30% and could measure the positions of > 3 × 10 14 M halos to < 5 and < 10 14 M to within 1 . In this paper, we present a brief overview of the winning algorithms with links to available code. We also discuss the implications of the experiment for future citizen science competitions.

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Image analysis for cosmology: Shape measurement challenge review & results from the Mapping Dark Matter challenge

Cited by 10 publications

References 24 publications

Weak Lensing Data and Condensed Neutrino Objects

Weak Lensing Data and Condensed Neutrino Objects

Structure Formation in Modified Gravity Cosmologies

Observing Dark Worlds: A crowdsourcing experiment for dark matter mapping

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