Geometry and growth contributions to cosmic shear observables
We explore the sensitivity of weaklensing 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 raytracing darkmatteronly Nbody 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 nonGaussian 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 growthonly effects, but with the correlation between the two parameters switching sign. Furthermore, thesemore »
 Authors:

^{[1]};
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^{[2]}
 Columbia Univ., New York, NY (United States)
 Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
 Publication Date:
 Grant/Contract Number:
 AC0276SF00515; ACI1053575; AST1210877
 Type:
 Accepted Manuscript
 Journal Name:
 Physical Review D
 Additional Journal Information:
 Journal Volume: 96; Journal Issue: 2; Journal ID: ISSN 24700010
 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 weaklensing 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 raytracing darkmatteronly Nbody 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 nonGaussian 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 growthonly effects, but with the correlation between the two parameters switching sign. Furthermore, these results shed light on the origin of the cosmology sensitivity of nonGaussian 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}
}