Improved constraints on the primordial power spectrum at small scales from ultracompact minihalos

By T. Bringmann, Pat Scott, Yashar Akrami. 2011

193 citations recorded by the source corpus.

For a Gaussian spectrum of primordial density fluctuations, ultracompact minihalos (UCMHs) of dark matter are expected to be produced in much greater abundance than, e.g., primordial black holes. Forming shortly after matter-radiation equality, these objects would develop very dense and spiky dark matter profiles. In the standard scenario where dark matter consists of thermally produced, weakly interacting massive particles, UCMHs could thus appear as highly luminous gamma-ray sources or leave an imprint in the cosmic microwave background by changing the reionization history of the Universe. We derive corresponding limits on the cosmic abundance of UCMHs at different epochs and translate them into constraints on the primordial power spectrum. We find the resulting constraints to be quite severe, especially at length scales much smaller than what can be directly probed by the cosmic microwave background or large-scale structure observations. We use our results to provide an updated compilation of the best available constraints on the power of density fluctuations on all scales, ranging from the present-day horizon to scales more than 20 orders of magnitude smaller.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/f2ac2db0968c66b9264b5fb30fa0a217aa34f6c2

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Marco Peloso
2. C. Byrnes
3. Juan García-Bellido
4. E. Pajer
5. J. Silk
6. S. Young
7. R. Cai
8. Julien Lesgourgues

In Nuclear and High Energy Physics

1. Marco Peloso
2. Juan García-Bellido
3. C. Byrnes
4. T. Bringmann
5. E. Pajer
6. C. Unal
7. J. Silk
8. N. Barnaby

Citations in the corpus

• Semianalytic calculation of gravitational wave spectrum nonlinearly induced from primordial curvature perturbations (2018, unknown): “ture perturbations by -distortion of CMB [43,44], change of baryon-to-photon ratio [45] and the neutron-to-proton ratio [46] (see also Ref. [47]) in BBN, and overproduction of ultracompact minihalos [48,49] or PBHs (for reviews of constraints, see e.g. Refs. [33,50,51]). 15 Note added Ref. [52] appe”
• Gauge Field Production in Axion Inflation: Consequences for Monodromy, non-Gaussianity in the CMB, and Gravitational Waves at Interferometers (2011, background): “Although probes of primordial perturbations at these scales might be less sensitive, and more model dependent (for instance, interesting limits can be obtained if one assumes that the dark matter consists on neutralinos; see [73] for a summary of limits at various scales) the signal is predicted to ”
• Scalaron from R2-gravity as a heavy field (2017, background): “This will make the enhancement of power spectrum at a very small scale beyond the CMB or LSS observations, where there is basically only very loose constraint [65].”
• Non-Gaussianity and the induced gravitational wave background (2021, background): “The later stages of inflation are only weakly constrained by (the nonobservation of) spectral distortions in the CMB [15], as well as the absence of high-energy γ rays from ultracompact minihalos [16].”
• Femtolensing by dark matter revisited (2018, background): “[53] for an approach to estimate the size of the core).”
• Primordial black holes and gravitational waves from parametric amplification of curvature perturbations (2019, background): “rbations originates from the periodic structure of the in ationary potential with the parameter set 2(blue), set 3(green), set 4(purple) in Tab.1, and constraint from cosmic microwave background (CMB [47]). { 6 { 3 PBH formation Now we study the formation of PBHs due to the enhancement of the power ”
• Steepest growth of the power spectrum and primordial black holes (2018, methodology): “[117], but unlike [117] we do not include constraints from ultracompact minihalos (UCMHs) since they rely on a WIMP DM scenario.”
• PRISM (Polarized Radiation Imaging and Spectroscopy Mission): an extended white paper (2013, background): “ently constrain the amplitude and spectral index of the primordial power spectrum around pivot scale kˇ45Mpc 1, superseding the constraint deduced from ultracompact minihalos or black hole abundances [23] by at least 2 orders of magnitude. The signatures of decaying particles will furthermore indepe”
• Primordial Black Holes from Polynomial Potentials in Single Field Inflation (2017, unknown): “[21]).”
• Primordial black holes with an accurate QCD equation of state (2018, background): “Mpc−1), the amplitude of the primordial curvature power spectrum is well measured by CMB and LSS observations to be around 10−9.”
• DarkSUSY 6: an advanced tool to compute dark matter properties numerically (2018, background): “• The core library contains a new set of functionalities to compute limits [29, 30] on DM models from the formation of ultracompact minihalos [31–33].”
• Gravitational wave signatures of inflationary models from Primordial Black Hole dark matter (2017, background): “We have currently little or no direct experimental information on the physics of inflation at later times/smaller scales, apart from the limits on the amount of scalar perturbations resulting from bounds on PBH and ultracompact minihalos [78, 79].”