Tidal streams from axion miniclusters and direct axion searches

Tinyakov, P.; Tkachev, I.; Zioutas, K.

doi:10.1088/1475-7516/2016/01/035

Cited by 90 publications

(142 citation statements)

References 29 publications

Supporting

Mentioning

138

Contrasting

Order By: Relevance

“…The results of [205] show the sensitivity of P d on the modeling of the halo potential and stellar populations. While eccentric orbits reduce the relative importance of disk stars compared to previous estimates by [37], including bulge and halo stars compensates this reduction, leading to a similar total result. More importantly, using an isothermal instead of an NFW halo model increases the disruption probability by bulge and halo stars, and in turn the probability of crossing an axion tidal stream, by almost a factor of three.…”

Section: Tidal Destructionsupporting

confidence: 52%

“…Disrupted miniclusters form tidal streams with densities lower than ρ mc by a factor inversely proportional to their volume growth R mc /v mc t mc , where t mc is the age of the stream [37]. In contrast with the negligibly low probability of encountering a minicluster during the lifetime a terrestrial axion detection experiment, the larger volume filling factor of axion streams enhances the chances of crossing a stream with relative overdensity ∼ 10 to approximately one every 20 years [37]. This motivates more detailed modeling of the disruption probability in order to obtain better forecasts for experimental constraints.…”

Section: Tidal Destructionmentioning

confidence: 99%

See 1 more Smart Citation

Small-scale structure of fuzzy and axion-like dark matter

Niemeyer

2020

Progress in Particle and Nuclear Physics

163

View full text Add to dashboard Cite

Axion-like particle (ALP) dark matter shows distinctive behavior on scales where wavelike effects dominate over self-gravity. Ultralight axions are candidates for fuzzy dark matter (FDM) whose de Broglie wavelength in virialized halos reaches scales of kiloparsecs. Important features of FDM scenarios are the formation of solitonic halo cores, suppressed small-scale perturbations, and enhanced gravitational relaxation. More massive ALPs, including the QCD axion, behave like CDM on galactic scales but may be clumped into axion miniclusters if they were produced after inflation. Just as FDM halos, axion miniclusters may host the formation of coherent bound objects (axion stars) by Bose-Einstein condensation. This article presents a selection of topics in this field that are currently under active investigation.

show abstract

Section: Tidal Destructionsupporting

confidence: 52%

Section: Tidal Destructionmentioning

confidence: 99%

Small-scale structure of fuzzy and axion-like dark matter

Niemeyer

2020

Progress in Particle and Nuclear Physics

163

View full text Add to dashboard Cite

show abstract

“…If axions are ever detected directly in the lab, then tidal stripping of miniclusters allows f MC to be measured from the phase-space distribution [36,43]. Independently of f MC , axions in the mass range accessible to microlensing can be detected via the force they mediate using the proposed experiment "ARIADNE" [49].…”

Section: Prl 119 021101 (2017) P H Y S I C a L R E V I E W L E T T Ementioning

confidence: 99%

“…The presence of f MC as a free parameter accounts for the fact that, due to the axion population from topological defect decay and the effects of, e.g., tidal stripping [36], only a fraction of axions end up bound in miniclusters.…”

mentioning

confidence: 99%

Searching for the QCD Axion with Gravitational Microlensing

Fairbairn¹,

Marsh²,

Quevillon³

2017

Phys. Rev. Lett.

View full text Add to dashboard Cite

The phase transition responsible for axion dark matter production can create large amplitude isocurvature perturbations which collapse into dense objects known as axion miniclusters. We use microlensing data from the EROS survey, and from recent observations with the Subaru Hyper Suprime Cam to place constraints on the minicluster scenario. We compute the microlensing event rate for miniclusters treating them as spatially extended objects. Using the published bounds on the number of microlensing events we bound the fraction of DM collapsed into miniclusters, fMC. For an axion with temperature dependent mass consistent with the QCD axion we find fMC < 0.083(ma/100 µeV) 0.12 , which represents the first observational constraint on the minicluster fraction. We forecast that a high-efficiency observation of around ten nights with Subaru would be sufficient to constrain fMC 0.004 over the entire QCD axion mass range. We make various approximations to derive these constraints and dedicated analyses by the observing teams of EROS and Subaru are necessary to confirm our results. If accurate theoretical predictions for fMC can be made in future then microlensing can be used to exclude, or discover, the QCD axion. Further details of our computations are presented in a companion paper [1].

show abstract

“…The precise nature of the substructure in our vicinity must be modeled numerically, but we can get a sense of which objects survive using simple estimates, following Refs. [38,76]. Evolution of DM substructure has been extensively studied in the context of CDM and axion-like particles.…”

Section: A Minicluster Survivalmentioning

confidence: 99%

Imprints of the early Universe on axion dark matter substructure

2020

View full text Add to dashboard Cite

Despite considerable experimental progress, large parts of the axion-like particle (ALP) parameter space remain difficult to probe in terrestrial experiments. In some cases, however, small-scale structure of the ALP dark matter (DM) distribution is strongly enhanced, offering opportunities for astrophysical tests. Such an enhancement can be produced by a period of pre-nucleosynthesis early matter domination (EMD). This cosmology arises in many ultraviolet completions and generates the correct relic abundance for weak coupling fa ∼ 10 16 GeV, ALP masses in the range 10 −13 eV < ma < 1 eV, and without fine-tuning of the initial misalignment angle. This range includes the QCD axion around 10 −9 −10 −8 eV. EMD enhances the growth of ALP small-scale structure, leading to the formation of dense ALP miniclusters. We study the interplay between the initial ALP oscillation, reheating temperature, and effective pressure to provide analytic estimates of the minicluster abundance and properties. ALP miniclusters in the EMD cosmology are denser and more abundant than in ΛCDM. While enhanced substructure generically reduces the prospects of direct detection experiments, we show that pulsar timing and lensing observations can discover these minihalos over a large range of ALP masses and reheating temperatures.

show abstract

Tidal streams from axion miniclusters and direct axion searches

Cited by 90 publications

References 29 publications

Small-scale structure of fuzzy and axion-like dark matter

Small-scale structure of fuzzy and axion-like dark matter

Searching for the QCD Axion with Gravitational Microlensing

Imprints of the early Universe on axion dark matter substructure

Contact Info

Product

Resources

About