Search Publications
Axion and neutrino bounds improved with new calibrations of the tip of the red-giant branch using geometric distance determinations
Capozzi, Francesco; Raffelt, Georg
The brightness of the tip of the red-giant branch (TRGB) allows one to constrain novel energy losses that would lead to a larger core mass at helium ignition and, thus, to a brighter TRGB than expected by standard stellar models. The required absolute TRGB calibrations strongly improve with reliable geometric distances that have become available f…
Science with the TianQin Observatory: Preliminary results on Galactic double white dwarf binaries
Huang, Shun-Jia; Hu, Yi-Ming; Korol, Valeriya +6 more
We explore the prospects of detecting Galactic double white dwarf (DWD) binaries with the space-based gravitational wave (GW) observatory TianQin. In this work, we analyze both a sample of currently known DWDs and a realistic synthetic population of DWDs to assess the number of guaranteed detections and the full capacity of the mission. We find th…
Velocity substructure from Gaia and direct searches for dark matter
Belokurov, Vasily; Evans, N. Wyn; Myeong, GyuChul +2 more
Data from the Gaia satellite show that the solar neighborhood of the Milky Way's stellar halo is imprinted with substructure from several accretion events. Evidence of these events is found in "the shards," stars clustering with high significance in both action space and metallicity. Stars in the shards share a common origin, likely as ancient sat…
Ghostly galaxies as solitons of Bose-Einstein dark matter
Broadhurst, Tom; Smoot, George F.; De Martino, Ivan +2 more
The large dark cores of common dwarf galaxies are unexplained by the standard heavy particle interpretation of dark matter. This puzzle is exacerbated by the discovery of a very large but barely visible, dark matter dominated galaxy Antlia II orbiting the Milky Way, uncovered by tracking star motions with the Ĝaia satellite. Although Antlia II has…
Constraints on dark matter-nucleon effective couplings in the presence of kinematically distinct halo substructures using the DEAP-3600 detector
Willis, J.; Chen, Y.; Ward, M. +86 more
DEAP-3600 is a single-phase liquid argon detector aiming to directly detect weakly interacting massive particles (WIMPs), located at SNOLAB (Sudbury, Canada). After analyzing data taken during the first year of operation, a null result was used to place an upper bound on the WIMP-nucleon, spin-independent, isoscalar cross section. This study reint…
Effective J -factors for Milky Way dwarf spheroidal galaxies with velocity-dependent annihilation
Pace, Andrew B.; Kumar, Jason; Runburg, Jack +2 more
We calculate the effective J -factors, which determine the strength of indirect detection signals from dark matter annihilation, for 25 dwarf spheroidal galaxies (dSphs). We consider several well-motivated assumptions for the relative velocity dependence of the dark matter annihilation cross section: σAv : s -wave (velocity independent)…
Power of halometry
Van Tilburg, Ken; Weiner, Neal; Mishra-Sharma, Siddharth
Astrometric weak gravitational lensing is a powerful probe of the distribution of matter on sub-Galactic scales, which harbor important information about the fundamental nature of dark matter. We propose a novel method that utilizes angular power spectra to search for the correlated pattern of apparent motions of celestial objects induced from tim…
Implications of the Gaia sausage for dark matter nuclear interactions
Buch, Jatan; Leung, John Shing Chau; Fan, JiJi
The advent of the Gaia era has led to potentially revolutionary understanding of dark matter (DM) dynamics in our galaxy, which has important consequences for direct detection (DD) experiments. In this paper, we study how the empirical DM velocity distribution inferred from Gaia-sausage, a dominant substructure in the solar neighborhood, affects t…
Monte Carlo control loops for cosmic shear cosmology with DES Year 1 data
Smith, M.; Annis, J.; Bertin, E. +53 more
Weak lensing by large-scale structure is a powerful probe of cosmology and of the dark universe. This cosmic shear technique relies on the accurate measurement of the shapes and redshifts of background galaxies and requires precise control of systematic errors. Monte Carlo control loops (MCCL) is a forward modeling method designed to tackle this p…
Astrometric effects of gravitational wave backgrounds with nonluminal propagation speeds
Gilmore, Gerard; Mihaylov, Deyan P.; Moore, Christopher J. +2 more
A passing gravitational wave causes a deflection in the apparent astrometric positions of distant stars. The effect of the speed of the gravitational wave on this astrometric shift is discussed. A stochastic background of gravitational waves would result in a pattern of astrometric deflections which are correlated on large angular scales. These co…