Search Publications
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…
Primordial black holes and oscillating gravitational waves in slow-roll and slow-climb inflation with an intermediate noninflationary phase
Wu, Puxun; Yu, Hongwei; Fu, Chengjie
We propose a new single field inflation model in which the usual slow-roll inflation is joined to a new period of slow-climb and slow-roll inflation through a short intermediate noninflationary phase. We then show that primordial curvature perturbations can be enhanced at small scales, a sizable amount of primordial black holes (PBHs) can be produ…
Primordial black holes and gravitational waves in nonstandard cosmologies
Mohanty, Subhendra; Parashari, Priyank; Bhattacharya, Sukannya
For primordial black holes (PBHs) to form a considerable fraction of cold dark matter, the required amplitude of primordial scalar perturbations is quite large (Pζ(k )∼10-2) if PBH is formed in radiation epoch. In alternate cosmological histories, where additional epoch of arbitrary equation of state precede radiation epoch, …
Testing interacting dark matter and dark energy model with cosmological data
Chen, Xuelei; Ma, Yin-Zhe; Cheng, Gong +2 more
We investigate the model of dark matter-dark energy (DM-DE) interaction with coupling strength proportional to the multiplication of dark sector densities with different power indices Q =γ ρcαρdβ. We first investigate the modification of the cosmic expansion history, and then further develop the formalis…
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…
Testing general relativity with x-ray reflection spectroscopy: The Konoplya-Rezzolla-Zhidenko parametrization
Tripathi, Ashutosh; Abdikamalov, Askar B.; Ayzenberg, Dimitry +6 more
X-ray reflection spectroscopy is a promising technique for testing general relativity in the strong-field regime as it can be used to test the Kerr black hole hypothesis. In this context, the parametrically deformed black hole metrics proposed by Konoplya, Rezzolla, and Zhidenko [Phys. Rev. D 93, 064015 (2016), 10.1103/PhysRevD.93.064015] form an …
Neutrino emission from an off-axis jet driven by the tidal disruption event AT2019dsg
Liu, Ruo-Yu; Wang, Xiang-Yu; Xi, Shao-Qiang
Recently, a high-energy muon neutrino event was detected in association with a tidal disruption event (TDE) AT2019dsg at the time about 150 days after the peak of the optical/UV luminosity. We propose that such an association could be interpreted as arising from hadronic interactions between relativistic protons accelerated in the jet launched fro…
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…
Diffusion in unimodular gravity: Analytical solutions, late-time acceleration, and cosmological constraints
Corral, Cristóbal; Cruz, Norman; González, Esteban
Unimodular gravity is an appealing approach to address the cosmological constant problem. In this scenario, the vacuum energy density of quantum fields does not gravitate and the cosmological constant appears merely as an integration constant. Recently, it has been shown that energy diffusion that may arise in quantum gravity and in theories with …