Search Publications
Hot axions and the H0 tension
Notari, Alessio; D'Eramo, Francesco; Ferreira, Ricardo Z. +1 more
Scattering and decay processes of thermal bath particles involving heavy leptons can dump hot axions in the primordial plasma around the QCD phase transition. We compute their relic density, parameterized by an effective number ΔNeff of additional neutrinos. For couplings allowed by current bounds, production via scattering yields ΔN
Halometry from astrometry
Van Tilburg, Ken; Weiner, Neal; Taki, Anna-Maria
Halometry—mapping out the spectrum, location, and kinematics of nonluminous structures inside the Galactic halo—can be realized via variable weak gravitational lensing of the apparent motions of stars and other luminous background sources. Modern astrometric surveys provide unprecedented positional precision along with a leap in the number of cata…
Anatomy of Eddington-like inversion methods in the context of dark matter searches
Lacroix, Thomas; Stref, Martin; Lavalle, Julien
Irrespective of the dark matter (DM) candidate, several potentially observable signatures derive from the velocity distribution of DM in halos, in particular in the Milky Way (MW) halo. Examples include direct searches for weakly-interacting massive particles (WIMPs), p-wave suppressed or Sommerfeld-enhanced annihilation signals, microlensing even…
The metal-poor stellar halo in RAVE-TGAS and its implications for the velocity distribution of dark matter
Lisanti, Mariangela; Herzog-Arbeitman, Jonah; Necib, Lina
The local velocity distribution of dark matter plays an integral role in interpreting the results from direct detection experiments. We previously showed that metal-poor halo stars serve as excellent tracers of the virialized dark matter velocity distribution using a high-resolution hydrodynamic simulation of a Milky Way-like halo. In this paper, …
Fast point spread function modeling with deep learning
Herbel, Jörg; Amara, Adam; Refregier, Alexandre +2 more
Modeling the Point Spread Function (PSF) of wide-field surveys is vital for many astrophysical applications and cosmological probes including weak gravitational lensing. The PSF smears the image of any recorded object and therefore needs to be taken into account when inferring properties of galaxies from astronomical images. In the case of cosmic …
The PAU Survey: a forward modeling approach for narrow-band imaging
Tortorelli, Luca; Della Bruna, Lorenza; Herbel, Jörg +18 more
Weak gravitational lensing is a powerful probe of the dark sector, once measurement systematic errors can be controlled. In [1], a calibration method based on forward modeling, called MCCL, was proposed. This relies on fast image simulations (e.g., UFig [2,3]}) that capture the key features of galaxy populations and measurement effects. The MCCL a…
Stability of condensed fuzzy dark matter halos
Eby, Joshua; Leembruggen, Madelyn; Suranyi, Peter +1 more
Stability properties of gravitationally bound condensates composed of ultralight axionic Fuzzy Dark Matter (FDM) are studied. Previous work has shown that astrophysical collisions could make self-gravitating condensates structurally unstable, making them prone to collapse and decay; in the context of FDM, we reexamine the relevant timescales using…