Effects of Unstable Dark Matter on Large-Scale Structure and Constraints from Future Surveys

Abstract

In this paper we explore the effect of decaying dark matter (DDM) on large-scale structure and possible constraints from galaxy imaging surveys. DDM models have been studied, in part, as a way to address apparent discrepancies between the predictions of standard cold dark matter models and observations of galactic structure. Our study is aimed at developing independent constraints on these models. In such models, DDM decays into a less massive, stable dark matter (SDM) particle and a significantly lighter particle. The small mass splitting between the parent DDM and the daughter SDM provides the SDM with a recoil or "kick" velocity vk, inducing a free-streaming suppression of matter fluctuations. This suppression may be probed via weak lensing power spectra measured by a number of forthcoming imaging surveys that aim primarily to constrain dark energy. Using scales on which linear perturbation theory alone is valid (multipoles < 300), surveys like Euclid or LSST can be sensitive to vk > 90 km/s for lifetimes ~ 1-5 Gyr. To estimate more aggressive constraints, we model nonlinear corrections to lensing power using a simple halo evolution model that is in good agreement with numerical simulations. In our most ambitious forecasts, using multipoles < 3000, we find that imaging surveys can be sensitive to vk ~ 10 km/s for lifetimes < 10 Gyr. Lensing will provide a particularly interesting complement to existing constraints in that they will probe the long lifetime regime far better than contemporary techniques. A caveat to these ambitious forecasts is that the evolution of perturbations on nonlinear scales will need to be well calibrated by numerical simulations before they can be realized. This work motivates the pursuit of such a numerical simulation campaign to constrain dark matter with cosmological weak lensing.

15 pages, 7 figures. Submitted to PRD

References in corpus (14)

• Effects of Baryons and Dissipation on the Matter Power Spectrum
• Can sterile neutrinos be the dark matter?
• Calibrating Redshift Distributions Beyond Spectroscopic Limits with Cross-Correlations
• Impact of massive neutrinos on nonlinear matter power spectrum
• Finding Evidence for Massive Neutrinos using 3D Weak Lensing
• Self Calibration of Tomographic Weak Lensing for the Physics of Baryons to Constrain Dark Energy
• Cosmic variance of weak lensing surveys in the non-Gaussian regime
• Dark-Matter Decays and Self-Gravitating Halos
• Dark-matter decays and Milky Way satellite galaxies
• Constraining warm dark matter with cosmic shear power spectra
• Supernovae, Lensed CMB and Dark Energy
• A Model For Late Dark Matter Decay
• Weak Gravitational Lensing as a Method to Constrain Unstable Dark Matter
• A Comparison of Weak Lensing Measurements From Ground- and Space-Based Facilities

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