Search Publications
LISA Pathfinder micronewton cold gas thrusters: In-flight characterization
Mendes, L.; Russano, G.; Lloro, I. +76 more
The LISA Pathfinder (LPF) mission has demonstrated the ability to limit and measure the fluctuations in acceleration between two free falling test masses down to sub-femto-g levels. One of the key elements to achieve such a level of residual acceleration is the drag free control. In this scheme the spacecraft is used as a shield against any extern…
Light dark matter from leptogenesis
Falkowski, Adam; Kuflik, Eric; Levi, Noam +1 more
We consider the implications of a shared production mechanism between the baryon asymmetry of the universe and the relic abundance of dark matter, that does not result in matching asymmetries. We present a simple model within a two sector leptogenesis framework, in which right handed sterile neutrinos decay out of equilibrium to both the standard …
Cosmological discordances. III. More on measure properties, large-scale-structure constraints, the Hubble constant and Planck data
Ishak, Mustapha; Lin, Weikang; Garcia-Quintero, Cristhian +1 more
Consistency between cosmological datasets is essential for ongoing and future cosmological analyses. We first investigate the questions of stability and applicability of some moment-based inconsistency measures to multiple datasets. We show that the recently introduced index of inconsistency (IOI) is numerically stable while it can be applied to m…
Constraining the Johannsen deformation parameter ɛ3 with black hole x-ray data
Tripathi, Ashutosh; Abdikamalov, Askar B.; Ayzenberg, Dimitry +2 more
We extend our previous work on tests of the Kerr black hole hypothesis using x-ray reflection spectroscopy and we infer observational constraints on the Johannsen deformation parameter ɛ3 . We analyze a NuSTAR observation of the stellar-mass black hole in GS 1354-645, Suzaku data of the supermassive black holes in Ark 564, 1H0419-577, a…
General study of chameleon fifth force in gravity space experiments
Bergé, Joel; Pernot-Borràs, Martin; Uzan, Jean-Philippe +1 more
In this article we investigate the profile of the scalar field of a scalar-tensor theory subject to the chameleon mechanism in the context of gravity space missions like the MICROSCOPE experiment. We analyze the experimental situations for models with an inverse power-law potential that can in principle induce a fifth force inside the satellite, a…
Observationally inferred dark matter phase-space distribution and direct detection experiments
Mandal, Sayan; Majumdar, Subhabrata; Rentala, Vikram +1 more
We present a detailed analysis of the effect of an observationally determined dark matter (DM) velocity distribution function (VDF) of the Milky Way (MW) on DM direct detection rates. We go beyond local kinematic tracers and use rotation curve data up to 200 kpc to construct a MW mass model and self-consistently determine the local phase-space dis…
Detecting the orbital motion of nearby supermassive black hole binaries with Gaia
Loeb, Abraham; D'Orazio, Daniel J.
We show that a 10-yr Gaia mission could astrometrically detect the orbital motion of ∼1 subparsec separation supermassive black hole binary in the heart of nearby, bright active galactic nuclei (AGN). Candidate AGN lie out to a redshift of z =0.02 and in the V-band magnitude range 10 ≲mV≲13 . The distribution of detectable binary masses…
Arbitrariness of potentials in interacting quintessence models
Bamba, Kazuharu; Roy, Nandan
Though we have entered an era of high precision cosmology the form of the quintessence potentials still remain arbitrary. In this work we explore the interacting quintessence models considering a parametrization of the quintessence potentials and tried to constrain the form of potentials using the recent cosmological observations. The particular p…
Direct detection anomalies in light of G A I A data
Buckley, Matthew R.; Mohlabeng, Gopolang; Murphy, Christopher W.
Measurements from the GAIA satellite have greatly increased our knowledge of the dark matter velocity distributions in the Solar neighborhood. There is evidence for multiple cold structures nearby, including a high-velocity stream counterrotating relative to the Sun. This stream could significantly alter the spectrum of recoil energies and increas…
Novel methods to measure the gravitational constant in space
Mendes, L.; Russano, G.; Nofrarias, M. +76 more
We present two novel methods, tested by LISA Pathfinder, to measure the gravitational constant G for the first time in space. Experiment 1 uses electrostatic suspension forces to measure a change in acceleration of a test mass due to a displaced source mass. Experiment 2 measures a change in relative acceleration between two test masses due to a s…