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Title: Geometry and growth contributions to cosmic shear observables

We explore the sensitivity of weak-lensing observables to the expansion history of the Universe and to the growth of cosmic structures, as well as the relative contribution of both effects to constraining cosmological parameters. We utilize ray-tracing dark-matter-only N-body simulations and validate our technique by comparing our results for the convergence power spectrum with analytic results from past studies. We then extend our analysis to non-Gaussian observables which cannot be easily treated analytically. We study the convergence (equilateral) bispectrum and two topological observables, lensing peaks and Minkowski functionals, focusing on their sensitivity to the matter density Ω m and the dark energy equation of state w. We find that a cancellation between the geometry and growth effects is a common feature for all observables and exists at the map level. It weakens the overall sensitivity by factors of up to 3 and 1.5 for w and Ω m, respectively, with the bispectrum worst affected. However, combining geometry and growth information alleviates the degeneracy between Ω m and w from either effect alone. As a result, the magnitudes of marginalized errors remain similar to those obtained from growth-only effects, but with the correlation between the two parameters switching sign. Furthermore, thesemore » results shed light on the origin of the cosmology sensitivity of non-Gaussian statistics and should be useful in optimizing combinations of observables.« less
Authors:
 [1] ;  [1] ;  [1] ;  [2]
  1. Columbia Univ., New York, NY (United States)
  2. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-76SF00515; ACI-1053575; AST-1210877
Type:
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 96; Journal Issue: 2; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; Weak Gravitational Lensing
OSTI Identifier:
1374384

Matilla, Jose Manuel Zorrilla, Haiman, Zoltan, Petri, Andrea, and Namikawa, Toshiya. Geometry and growth contributions to cosmic shear observables. United States: N. p., Web. doi:10.1103/PhysRevD.96.023513.
Matilla, Jose Manuel Zorrilla, Haiman, Zoltan, Petri, Andrea, & Namikawa, Toshiya. Geometry and growth contributions to cosmic shear observables. United States. doi:10.1103/PhysRevD.96.023513.
Matilla, Jose Manuel Zorrilla, Haiman, Zoltan, Petri, Andrea, and Namikawa, Toshiya. 2017. "Geometry and growth contributions to cosmic shear observables". United States. doi:10.1103/PhysRevD.96.023513. https://www.osti.gov/servlets/purl/1374384.
@article{osti_1374384,
title = {Geometry and growth contributions to cosmic shear observables},
author = {Matilla, Jose Manuel Zorrilla and Haiman, Zoltan and Petri, Andrea and Namikawa, Toshiya},
abstractNote = {We explore the sensitivity of weak-lensing observables to the expansion history of the Universe and to the growth of cosmic structures, as well as the relative contribution of both effects to constraining cosmological parameters. We utilize ray-tracing dark-matter-only N-body simulations and validate our technique by comparing our results for the convergence power spectrum with analytic results from past studies. We then extend our analysis to non-Gaussian observables which cannot be easily treated analytically. We study the convergence (equilateral) bispectrum and two topological observables, lensing peaks and Minkowski functionals, focusing on their sensitivity to the matter density Ωm and the dark energy equation of state w. We find that a cancellation between the geometry and growth effects is a common feature for all observables and exists at the map level. It weakens the overall sensitivity by factors of up to 3 and 1.5 for w and Ωm, respectively, with the bispectrum worst affected. However, combining geometry and growth information alleviates the degeneracy between Ωm and w from either effect alone. As a result, the magnitudes of marginalized errors remain similar to those obtained from growth-only effects, but with the correlation between the two parameters switching sign. Furthermore, these results shed light on the origin of the cosmology sensitivity of non-Gaussian statistics and should be useful in optimizing combinations of observables.},
doi = {10.1103/PhysRevD.96.023513},
journal = {Physical Review D},
number = 2,
volume = 96,
place = {United States},
year = {2017},
month = {7}
}