Axion minivoids and implications for direct detection

Eggemeier, B. ; O’Hare, C. A. J. ; Pierobon, G. ; Redondo, J. (Universidad de Zaragoza) ; Wong, Y. Y. Y.

Resumen: 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 miniclusters that trap up to ∼75% of the dark matter within asteroid-mass clumps. Axion miniclusters are physically tiny however, so haloscope experiments searching for axions directly on Earth are much more likely to be probing “minivoids”—the space in between miniclusters. This scenario seems like it ought to spell doom for haloscopes, but while these minivoids might be underdense, they are not totally devoid of axions. Using Schrödinger-Poisson and N-body simulations to evolve from realistic initial field configurations, we quantify the extent to which the local ambient dark matter density is suppressed in the postinflationary scenario. We find that a typical experimental measurement will sample an axion density that is only around 10% of the expected galactic dark matter density. Our results are taken as conservative estimates and have implications for experimental campaigns lasting longer than a few years, as well as broadband haloscopes that have sensitivity to transient signatures. We show that for a Oð(year)-long integration times, the measured dark matter density should be expected to vary by 20%–30%.

Idioma: Inglés

DOI: 10.1103/PhysRevD.107.083510

Año: 2023

Publicado en: Physical Review D 107, 8 (2023), 083510 [18 pp.]
ISSN: 2470-0010

Factor impacto JCR: 4.6 (2023)

Categ. JCR: PHYSICS, PARTICLES & FIELDS rank: 7 / 31 = 0.226 (2023) - Q1 - T1
Categ. JCR: ASTRONOMY & ASTROPHYSICS rank: 17 / 84 = 0.202 (2023) - Q1 - T1

Factor impacto CITESCORE: 9.3 - Nuclear and High Energy Physics (Q1)

Factor impacto SCIMAGO: 1.587 - Physics and Astronomy (miscellaneous) (Q1) - Nuclear and High Energy Physics (Q1)

Financiación: info:eu-repo/grantAgreement/ES/AEI-FEDER/PGC2018-095328-B-I00
Financiación: info:eu-repo/grantAgreement/ES/DGA/E12-7R
Financiación: info:eu-repo/grantAgreement/EC/H2020/674896/EU/The Elusives Enterprise: Asymmetries of the Invisible Universe/ELUSIVES

Tipo y forma: Article (Published version)

Área (Departamento): Área Física Teórica (Dpto. Física Teórica)