On model selection forecasting, dark energy and modified gravity

Heavens, Alan; Kitching, Thomas D.; Verde, Licia

doi:10.1111/j.1365-2966.2007.12134.x

Cited by 164 publications

(212 citation statements)

References 57 publications

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“…It is therefore more useful to combine lensing with other observations of large-scale structure to carry out robust tests of gravity, as shown in Sections 10.2.5 and 10.3.1 below. Tests of gravity that rely solely on lensing measurements can constrain specific models; alternatively lensing measurements with multiple redshift bins can probe the the growth of structure (e.g., [960]) which can be compared to the predictions of GR.…”

Section: Weak Gravitational Lensingmentioning

confidence: 99%

Beyond the cosmological standard model

et al. 2015

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After a decade and a half of research motivated by the accelerating universe, theory and experiment have a reached a certain level of maturity. The development of theoretical models beyond Λ or smooth dark energy, often called modified gravity, has led to broader insights into a path forward, and a host of observational and experimental tests have been developed. In this review we present the current state of the field and describe a framework for anticipating developments in the next decade. We identify the guiding principles for rigorous and consistent modifications of the standard model, and discuss the prospects for empirical tests.We begin by reviewing recent attempts to consistently modify Einstein gravity in the infrared, focusing on the notion that additional degrees of freedom introduced by the modification must "screen" themselves from local tests of gravity. We categorize screening mechanisms into three broad classes: mechanisms which become active in regions of high Newtonian potential, those in which first derivatives of the field become important, and those for which second derivatives of the field are important. Examples of the first class, such as f (R) gravity, employ the familiar chameleon or symmetron mechanisms, whereas examples of the last class are galileon and massive gravity theories, employing the Vainshtein mechanism. In each case, we describe the theories as effective theories and discuss prospects for completion in a more fundamental theory. We describe experimental tests of each class of theories, summarizing laboratory and solar system tests and describing in some detail astrophysical and cosmological tests. Finally, we discuss prospects for future tests which will be sensitive to different signatures of new physics in the gravitational sector.The review is structured so that those parts that are more relevant to theorists vs. observers/experimentalists are clearly indicated, in the hope that this will serve as a useful reference for both audiences, as well as helping those interested in bridging the gap between them.

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Section: Weak Gravitational Lensingmentioning

confidence: 99%

Beyond the cosmological standard model

et al. 2015

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“…The value of the CMB prior is shown in terms of f (φ) in the first column of Table 3 for each of the parameters. Since the LS is a future survey we also compared its results with a prediction of the Planck Fisher matrix (see Heavens et al 2007). The predicted Fisher matrix in Heavens et al (2007) assumes zero curvature (Ω m + Ω Λ = 1), therefore, we had to impose this constraint on our COSEBIs Fisher Matrices to add them.…”

Section: Assumptions and Parameter Settingsmentioning

confidence: 99%

Cosmic shear tomography and efficient data compression using COSEBIs

Asgari

Schneider

Simon

2012

A&A

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Context. Gravitational lensing is one of the leading tools in understanding the dark side of the Universe. The need for accurate, efficient and effective methods, which are able to extract this information along with other cosmological parameters from cosmic shear data is ever growing. Complete Orthogonal Sets of E-/B-Integrals (COSEBIs) is a recently developed statistical measure that encompasses the complete E-/B-mode separable information contained in the shear correlation functions measured on a finite angular range. Aims. The aim of the present work is to test the properties of this newly developed statistics for a higher-dimensional parameter space and to generalize and test it for shear tomography. Methods. We use Fisher analysis to study the effectiveness of COSEBIs. We show our results in terms of figure-of-merit quantities, based on Fisher matrices. Results. We find that a relatively small number of COSEBIs modes is always enough to saturate to the maximum information level. This number is always smaller for "logarithmic COSEBIs" than for "linear COSEBIs", and also depends on the number of redshift bins, the number and choice of cosmological parameters, as well as the survey characteristics. Conclusions. COSEBIs provide a very compact way of analyzing cosmic shear data, i.e., all the E-/B-mode separable second-order statistical information in the data is reduced to a small number of COSEBIs modes. Furthermore, with this method the arbitrariness in data binning is no longer an issue since the COSEBIs modes are discrete. Finally, the small number of modes also implies that covariances, and their inverse, are much more conveniently obtainable, e.g., from numerical simulations, than for the shear correlation functions themselves.

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“…Then, if the correct underlying model does contain certain systematics, in the incorrect model where we neglect them, the maximum of the expected likelihood will not, in general, be at the correct parameter values (see Heavens et al 2007, Fig. 1).…”

Section: Appendix A: Bias On Parameter Estimationmentioning

confidence: 99%

“…Heavens et al 2007;Camera et al 2011c). Two models are nested when the parameter space of the former (or 'simpler' model) is contained within that of the latter.…”

Section: Appendix A: Bias On Parameter Estimationmentioning

confidence: 99%

“…Weak lensing is particularly valuable because it probes both the background evolution of the Universe and the growth of cosmic structures. For this reason, it has been advocated as an optimal way to test dark matter (Bacon & Taylor 2003;Taylor et al 2004;Camera et al , 2015Shirasaki et al 2014), dark energy (Amendola et al 2008;Taylor et al 2007;Heavens et al 2006;Beynon et al 2012;Camera & Nishizawa 2013) and modified gravity (Ishak et al 2006;Heavens et al 2007;Tsujikawa & Tatekawa 2008;Schmidt 2008; ⋆ E-mail: stefano.camera@manchester.ac.uk 2010; Belloso et al 2011;Camera et al 2009Camera et al , 2011a, in particular in combination with galaxy number counts and other observables (Hu & Jain 2004;Jain & Zhang 2008;Camera et al 2012Camera et al , 2014.…”

Section: Introductionmentioning

confidence: 99%

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SKA weak lensing – III. Added value of multiwavelength synergies for the mitigation of systematics

Camera

Harrison

Bonaldi

et al. 2016

Mon. Not. R. Astron. Soc.

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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 optical/near-IR bands for mitigating systematic effects. We focus on three main classes of systematics: (i) experimental systematic errors in the observed shear; (ii) signal contamination by intrinsic alignments; and (iii) systematic effects due to an incorrect modelling of non-linear scales. First, we show that a comprehensive, multiwavelength analysis provides a self-calibration method for experimental systematic effects, only implying < 50% increment on the errors on cosmological parameters. We also illustrate how the cross-correlation between radio and optical/near-IR surveys alone is able to remove residual systematics with variance as large as 10 −5 , i.e. the same order of magnitude of the cosmological signal. This also opens the possibility of using such a cross-correlation as a means to detect unknown experimental systematics. Secondly, we demonstrate that, thanks to polarisation information, radio weak lensing surveys will be able to mitigate contamination by intrinsic alignments, in a way similar but fully complementary to available self-calibration methods based on position-shear correlations. Lastly, we illustrate how radio weak lensing experiments, reaching higher redshifts than those accessible to optical surveys, will probe dark energy and the growth of cosmic structures in régimes less contaminated by non-linearities in the matter perturbations. For instance, the higher-redshift bins of radio catalogues peak at z ≃ 0.8 − 1, whereas their optical/near-IR counterparts are limited to z 0.5 − 0.7. This translates into having a cosmological signal 2 to 5 times less contaminated by non-linear perturbations.

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On model selection forecasting, dark energy and modified gravity

Abstract: 13.02.13 KB. Accepted version ok to add to Spiral. RAS/Wile

Cited by 164 publications

References 57 publications

Beyond the cosmological standard model

Beyond the cosmological standard model

Cosmic shear tomography and efficient data compression using COSEBIs

SKA weak lensing – III. Added value of multiwavelength synergies for the mitigation of systematics

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