Weighted density fields as improved probes of modified gravity models

Abstract

When it comes to searches for extensions to general relativity, large efforts are being dedicated to accurate predictions for the power spectrum of density perturbations. While this observable is known to be sensitive to the gravitational theory, its efficiency as a diagnostic for gravity is significantly reduced when Solar System constraints are strictly adhered to. We show that this problem can be overcome by studying weigthed density fields. We propose a transformation of the density field for which the impact of modified gravity on the power spectrum can be increased by more than a factor of three. The signal is not only amplified, but the modified gravity features are shifted to larger scales which are less affected by baryonic physics. Furthermore, the overall signal-to-noise increases, which in principle makes identifying signatures of modified gravity with future galaxy surveys more feasible. While our analysis is focused on modified gravity, the technique can be applied to other problems in cosmology, such as the detection of neutrinos, the effects of baryons or baryon acoustic oscillations.

5 pages, 1 figure. Submitted to MNRAS Letters

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• Using the Marked Power Spectrum to Detect the Signature of Neutrinos in Large-Scale Structure
• The Novel Probes Project -- Tests of Gravity on Astrophysical Scales
• The Accuracy of Weak Lensing Simulations
• Marked clustering statistics in $f(R)$ gravity cosmologies
• Testing modified gravity using a marked correlation function
• Beyond delta: Tailoring marked statistics to reveal modified gravity
• Cosmological Probes of Structure Growth and Tests of Gravity
• Detecting Domain Walls in Laboratory Experiments
• Towards an optimal marked correlation function analysis for the detection of modified gravity
• Cosmological Constraints from Fourier Phase Statistics