Related papers: Axion Miniclusters Made Easy
When Peccei-Quinn (PQ) symmetry breaking happens after inflation, the axion field takes random values in causally disconnected regions. This leads to fluctuations of order one in the axion energy density around the QCD epoch. These…
The Peak-Patch algorithm is used to identify the densest minicluster seeds in the initial axion density field simulated from string decay. The fate of these dense seeds is found by tracking the subsequent gravitational collapse in…
We study the gravitational collapse of axion dark matter fluctuations in the post-inflationary scenario, so-called axion miniclusters, with N-body simulations. Largely confirming theoretical expectations, overdensities begin to collapse in…
If the symmetry breaking responsible for axion dark matter production occurs during the radiation-dominated epoch in the early Universe, then this produces large amplitude perturbations that collapse into dense objects known as axion…
The properties of axion miniclusters and of the voids between them can have very strong implications for the discovery of axions and the dark matter of the Universe. These properties can be strongly affected by axion dynamics in the early…
A consequence of QCD axion dark matter being born after inflation is the emergence of small-scale substructures known as miniclusters. Although miniclusters merge to form minihalos, this intrinsic granularity is expected to remain imprinted…
We identify axion miniclusters collapsing in the radiation-dominated era and follow them to redshift $z=99$ with N-body simulations. We find that the majority of the densest miniclusters end up in the center of larger minicluster halos at…
We study the small scale structure of axion dark matter in the post-inflationary scenario, which predicts the formation of low-mass, high-density clumps of gravitationally bound axions called axion miniclusters. To this end, we follow…
Axion miniclusters are dense bound structures of dark matter axions that are predicted to form in the post-inflationary Peccei-Quinn symmetry breaking scenario. Although dense, miniclusters can easily be perturbed or even become unbound by…
Previously, it has been established that axion dark matter (DM) is clustered to form clumps (axion miniclusters) with masses $M\sim10^{-12}M_\odot$. The passages of such clumps through the Earth are very rare events occurring once in $10^5$…
We compute the dark matter halo mass function using the excursion set formalism for a diffusive barrier with linearly drifting average which captures the main features of the ellipsoidal collapse model. We evaluate the non-Markovian…
In the scenario in which QCD axion dark matter is produced after inflation, the Universe is populated by large inhomogeneities on very small scales. Eventually, these fluctuations will collapse gravitationally to form dense axion…
The $\Lambda$CDM model predicts structure formation across a vast mass range, from massive clusters ($\sim10^{15}\,\text{M}_\odot$) to Earth-mass micro-haloes ($\sim 10^{-6} \, \text{M}_\odot$), resolving which far exceeds the capabilities…
Excursion set theory is a powerful and widely used tool for describing the distribution of dark matter haloes, but it is normally applied with simplifying approximations. We use numerical sampling methods to study the mass functions…
If dark matter is an axion-like-particle a significant fraction of the present day relic abundance could be concentrated in compact gravitationally bound miniclusters. We study the minicluster masses compatible with the dark matter relic…
We present a solution of the Schr\"odinger-Poisson system based on the WKB ansatz for the wave function. In this way we obtain a description of a gravitationally bound clump of axion dark matter by a superposition of energy eigenstates with…
Axionic dark matter can form miniclusters and minicluster halos from inhomogenuities in the early Universe. If MCHs are sufficiently massive, their existence can be revealed by small-scale gravitational tidal perturbation to halo-like…
Non-linear effects in the evolution of the axion field in the early Universe may lead to the formation of gravitationally bound clumps of axions, known as "miniclusters". Minicluster masses should be in the range $M_{\rm mc}\sim10^{-12}…
The excursion set model provides a convenient theoretical framework to derive dark matter halo abundances. This paper generalizes the model by introducing a more realistic merging and collapse process. A new parameter regulates the…
Shape estimates that quantify the halo anisotropic mass distribution are valuable parameters that provide information on their assembly process and evolution. Measurements of the mean shapes for a sample of cluster-sized halos can be used…