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Density split statistics: Joint model of counts and lensing in cells

Density split statistics: Joint model of counts and lensing in cells
Density split statistics: Joint model of counts and lensing in cells
We present density split statistics, a framework that studies lensing and counts-in-cells as a function of foreground galaxy density, thereby providing a large-scale measurement of both 2-point and 3-point statistics. Our method extends our earlier work on trough lensing and is summarized as follows: given a foreground (low redshift) population of galaxies, we divide the sky into subareas of equal size but distinct galaxy density. We then measure lensing around uniformly spaced points separately in each of these subareas, as well as counts-in-cells statistics (CiC). The lensing signals trace the matter density contrast around regions of fixed galaxy density. Through the CiC measurements this can be related to the density profile around regions of fixed matter density. Together, these measurements constitute a powerful probe of cosmology, the skewness of the density field and the connection of galaxies and matter. In this paper we show how to model both the density split lensing signal and CiC from basic ingredients: a non-linear power spectrum, clustering hierarchy coefficients from perturbation theory and a parametric model for galaxy bias and shot-noise. Using N-body simulations, we demonstrate that this model is sufficiently accurate for a cosmological analysis on year 1 data from the Dark Energy Survey.
1550-7998
1-34
Friedrich, O.
219eb084-560e-4c36-b2f5-b33a8b582c33
Smith, M.
8bdc74e1-a37b-434d-ae75-82763109bf7a
DES Collaboration
Friedrich, O.
219eb084-560e-4c36-b2f5-b33a8b582c33
Smith, M.
8bdc74e1-a37b-434d-ae75-82763109bf7a

Friedrich, O. and Smith, M. , DES Collaboration (2018) Density split statistics: Joint model of counts and lensing in cells. Physical Review D, 98, 1-34. (doi:10.1103/PhysRevD.98.023508).

Record type: Article

Abstract

We present density split statistics, a framework that studies lensing and counts-in-cells as a function of foreground galaxy density, thereby providing a large-scale measurement of both 2-point and 3-point statistics. Our method extends our earlier work on trough lensing and is summarized as follows: given a foreground (low redshift) population of galaxies, we divide the sky into subareas of equal size but distinct galaxy density. We then measure lensing around uniformly spaced points separately in each of these subareas, as well as counts-in-cells statistics (CiC). The lensing signals trace the matter density contrast around regions of fixed galaxy density. Through the CiC measurements this can be related to the density profile around regions of fixed matter density. Together, these measurements constitute a powerful probe of cosmology, the skewness of the density field and the connection of galaxies and matter. In this paper we show how to model both the density split lensing signal and CiC from basic ingredients: a non-linear power spectrum, clustering hierarchy coefficients from perturbation theory and a parametric model for galaxy bias and shot-noise. Using N-body simulations, we demonstrate that this model is sufficiently accurate for a cosmological analysis on year 1 data from the Dark Energy Survey.

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More information

e-pub ahead of print date: 13 July 2018
Published date: July 2018

Identifiers

Local EPrints ID: 424936
URI: https://eprints.soton.ac.uk/id/eprint/424936
ISSN: 1550-7998
PURE UUID: 8bd55644-d712-4ff5-87fb-153091934bf0
ORCID for M. Smith: ORCID iD orcid.org/0000-0002-3321-1432

Catalogue record

Date deposited: 05 Oct 2018 16:30
Last modified: 17 May 2019 00:30

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