Ballistic Dark Matter oscillates above ΛCDM

Das, Anirban; Dasgupta, Basudeb; Khatri, Rishi

doi:10.1088/1475-7516/2019/04/018

Cited by 17 publications

(9 citation statements)

References 79 publications

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“…interactions in the dark matter sector, forming pressure-gravity waves that are imprinted on the clustering signal. Dark acoustic oscillations have been predicted for scenarios of DM-photon (Boehm et al 2002) and DM-neutrino interactions (Mangano et al 2006;Wilkinson et al 2014), models including dark radiation (Ackerman et al 2009;Foot & Vagnozzi 2015Dessert et al 2019; ★ E-mail: timothee.schaeffer@uzh.ch † E-mail: aurel.schneider@uzh.ch Das et al 2019), dark atom scenarios (Cyr-Racine & Sigurdson 2013), or through alternative scenarios of inflation (Domènech & Kamionkowski 2019;Ballardini et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Dark acoustic oscillations: imprints on the matter power spectrum and the halo mass function

Schaeffer

Schneider

2021

Monthly Notices of the Royal Astronomical Society

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Many non-minimal dark matter scenarios lead to oscillatory features in the matter power spectrum induced by interactions either within the dark sector or with particles from the standard model. Observing such dark acoustic oscillations would therefore be a major step towards understanding dark matter. We investigate what happens to oscillatory features during the process of nonlinear structure formation. We show that at the level of the power spectrum, oscillations are smoothed out by nonlinear mode coupling, gradually disappearing towards lower redshifts. In the halo mass function, however, the oscillatory features remain visible until the present epoch. As a consequence, dark acoustic oscillations could be detectable in observations that are either based on the halo mass function or on the high-redshift power spectrum. We investigate the effect of such features on different observables, namely, the cluster mass function, the stellar-to-halo mass relation, and the Lyman-α flux power spectrum. We find that oscillatory features remain visible in all of these observables, but they are very extended and of low amplitude, making it challenging to detect them as distinct features in the data.

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Section: Introductionmentioning

confidence: 99%

Dark acoustic oscillations: imprints on the matter power spectrum and the halo mass function

Schaeffer

Schneider

2021

Monthly Notices of the Royal Astronomical Society

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“…We point out that we may also expect oscillatory signatures in the matter power spectrum [38], although such an analysis is beyond the scope of this work.…”

Section: Phenomenologymentioning

confidence: 97%

Reproductive freeze-in of self-interacting dark matter

2020

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We present a mechanism for dark matter (DM) production involving a self-interacting sector that at early times is ultrarelativistic but far underpopulated relative to thermal equilibrium (such initial conditions often arise, e.g., from inflaton decay). Although elastic scatterings can establish kinetic equilibrium we show that for a broad variety of self-interactions full equilibrium is never established despite the DM yield significantly evolving due to 2 → k (k > 2) processes (the DM carries no conserved quantum number nor asymmetry). During the active phase of the process, the DM to Standard Model temperature ratio falls rapidly, with DM kinetic energy being converted to DM mass, the inverse of the recently discussed "cannibal DM mechanism." As this evolution is an approach from an out-of-equilibrium to equilibrium state, entropy is not conserved. Potential observables and applications include self-interacting DM signatures in galaxies and clusters, dark acoustic oscillations, the alteration of free-streaming constraints, and possible easing of σ 8 and Hubble tensions.

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“…For example, for m s = 10 keV and λ s = 10 −6 we find a dec ≈ 2 × 10 −5 (corresponding to T SM,dec ≈ 10 eV). Such large values of a dec may affect the growth of density perturbations and hence potentially lead to modifications of the CMB [58]. We leave a study of these effects, which may strengthen the bound on the self-interaction cross section, to future work.…”

Section: (55)mentioning

confidence: 98%

Freeze-in production of decaying dark matter in five steps

Heeba

Kahlhoefer

Stöcker

2018

J. Cosmol. Astropart. Phys.

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We study the cosmological evolution and phenomenological properties of scalar bosons in the keV to MeV range that have a tiny mixing with the Standard Model Higgs boson. The mixing determines both the abundance of light scalars produced via the freezein mechanism and their lifetime. Intriguingly, the parameters required for such scalars to account for all of the dark matter in the present Universe generically predict lifetimes comparable to the sensitivity of present and future indirect detection experiments. In order to accurately determine the relic abundance of light scalars, we calculate freeze-in yields including effects from finite temperatures and quantum statistics and develop a new approach for solving the Boltzmann equation for number-changing processes in the dark sector. We find that light scalars can potentially explain the anomalous x-ray emission at 3.5 keV, while evading constraints from structure formation and predicting potentially observable self-interaction cross sections.

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Ballistic Dark Matter oscillates above ΛCDM

Cited by 17 publications

References 79 publications

Dark acoustic oscillations: imprints on the matter power spectrum and the halo mass function

Dark acoustic oscillations: imprints on the matter power spectrum and the halo mass function

Reproductive freeze-in of self-interacting dark matter

Freeze-in production of decaying dark matter in five steps

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