Search Publications
Constraints on a mixed model of dark matter particles and primordial black holes from the galactic 511 keV line
Cai, Rong-Gen; Ding, Yu-Chen; Yang, Xing-Yu +1 more
The galactic 511 keV gamma-ray line has been observed since 1970's, and was identified as the result of electron-positron annihilation, but the origin of such positrons is still not clear. Apart from the astrophysical explanations, the possibilities that such positrons come from dark matter (DM) annihilation are also widely studied. Primordial bla…
Improved treatment of dark matter capture in white dwarfs
Bell, Nicole F.; Ramirez-Quezada, Maura E.; Busoni, Giorgio +2 more
White dwarfs, the most abundant stellar remnants, provide a promising means of probing dark matter interactions, complimentary to terrestrial searches. The scattering of dark matter from stellar constituents leads to gravitational capture, with important observational consequences. In particular, white dwarf heating occurs due to the energy transf…
Dependence of dark matter - electron scattering on the galactic dark matter velocity distribution
Radick, Aria; Taki, Anna-Maria; Yu, Tien-Tien
The rate of dark matter-electron scattering depends on the underlying velocity distribution of the dark matter halo. Importantly, dark matter-electron scattering is particularly sensitive to the high-velocity tail, which differs significantly amongst the various dark matter halo models. In this work, we summarize the leading halo models and discus…
Don't cross the streams: caustics from fuzzy dark matter
Bovy, Jo; Dalal, Neal; Hui, Lam +1 more
We study how tidal streams from globular clusters may be used to constrain the mass of ultra-light dark matter particles, called `fuzzy' dark matter (FDM). A general feature of FDM models is the presence of ubiquitous density fluctuations in bound, virialized dark matter structures, on the scale of the de Broglie wavelength, arising from wave inte…
Magnetars and axion-like particles: probes with the hard X-ray spectrum
Sinha, Kuver; Guo, Huai-Ke; Fortin, Jean-François +2 more
Quiescent hard X-ray and soft gamma-ray emission from neutron stars constitute a promising frontier to explore axion-like-particles (ALPs). ALP production in the core peaks at energies of a few keV to a few hundreds of keV; subsequently, the ALPs escape and convert to photons in the magnetosphere. The emissivity goes as T6 while the con…
Constraining axion-like particles using the white dwarf initial-final mass relation
Dolan, Matthew J.; Hiskens, Frederick J.; Volkas, Raymond R.
Axion-like particles (ALPs), a class of pseudoscalars common to many extensions of the Standard Model, have the capacity to drain energy from the interiors of stars. Consequently, stellar evolution can be used to derive many constraints on ALPs. We study the influence that keV-MeV scale ALPs which interact exclusively with photons can exert on the…
Constraints on MeV dark matter and primordial black holes: Inverse Compton signals at the SKA
Kar, Arpan; Dutta, Bhaskar; Strigari, Louis E.
We investigate the possibilities for probing MeV dark matter (DM) particles and primordial black holes (PBHs) (for masses ~ 1015-1017 g) at the upcoming radio telescope SKA, using photon signals from the Inverse Compton (IC) effect within a galactic halo. Pair-annihilation or decay of MeV DM particles (into e+ e
Testing Primordial Black Holes with multi-band observations of the stochastic gravitational wave background
García-Bellido, Juan; Kuroyanagi, Sachiko; Braglia, Matteo
The mass distribution of Primordial Black Holes (PBHs) is affected by drops in the pressure of the early Universe plasma. For example, events in the standard model of particle physics, such as the W ±/Z 0 decoupling, the quark-hadron transition, the muon and pion becoming non-relativistic, and the annihilation of electrons an…
The PAU survey: measurement of narrow-band galaxy properties with approximate bayesian computation
Tortorelli, Luca; Amara, Adam; Refregier, Alexandre +22 more
Narrow-band imaging surveys allow the study of the spectral characteristics of galaxies without the need of performing their spectroscopic follow-up. In this work, we forward-model the Physics of the Accelerating Universe Survey (PAUS) narrow-band data. The aim is to improve the constraints on the spectral coefficients used to create the galaxy sp…
X-ray shapes of elliptical galaxies and implications for self-interacting dark matter
Jeltema, T.; McDaniel, A.; Profumo, S.
Several proposed models for dark matter posit the existence of self-interaction processes that can impact the shape of dark matter halos, making them more spherical than the ellipsoidal halos of collisionless dark matter. One method of probing the halo shapes, and thus the strength of the dark matter self-interaction, is by measuring the shape of …