English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We revise the cosmological phenomenology of Macroscopic Dark Matter (MDM)candidates, also commonly dubbed as Macros. A possible signature of MDM is thecapture of baryons from the cosmological plasma in the pre-recombination epoch,with the consequent injection of high-energy photons in the baryon-photonplasma. By keeping a phenomenological approach, we consider two broad classesof MDM in which Macros are composed either of ordinary matter or antimatter. Inboth scenarios, we also analyze the impact of a non-vanishing electric chargecarried by Macros. We derive constraints on the Macro parameter space fromthree cosmological processes: the change in the baryon density between the endof the Big Bang Nucleosynthesis (BBN) and the Cosmic Microwave Background (CMB)decoupling, the production of spectral distortions in the CMB and the kineticcoupling between charged MDM and baryons at the time of recombination. In thecase of neutral Macros we find that the tightest constraints are set by thebaryon density condition in most of the parameter space. For Macros composed ofordinary matter and with binding energy $I$, this leads to the following boundon the reduced cross-section: $\sigma_X/M_X \lesssim 6.8 \cdot 10^{-7}\left(I/\mathrm{MeV}\right)^{-1.56} \, \text{cm}^2 \, \text{g}^{-1}$. ChargedMacros with surface potential $V_X$, instead, are mainly constrained by thetight coupling with baryons, resulting in $\sigma_X/M_X \lesssim 2 \cdot10^{-11} \left(|V_X|/\mathrm{MeV}\right)^{-2} \text{cm}^2 \, \text{g}^{-1}$.Finally, we show that future CMB spectral distortions experiments, like PIXIEand SuperPIXIE, would have the sensitivity to probe larger regions of theparameter space: this would allow either for a possible evidence or for animprovement of the current bounds on Macros as dark matter candidates.

Updated cosmological constraints on Macroscopic Dark Matter