Search Publications
Primordial gravitational waves and the H0-tension problem
Benetti, Micol; Graef, Leila L.; Alcaniz, Jailson S.
We analyze the H0-tension problem in the context of models of the early universe that predict a blue tilted spectrum of primordial gravitational waves (GWs), which is a positive value of the tensor tilt nT. By considering the GW's contribution, NeffGW, to the effective number of relativistic degrees of f…
LISA Pathfinder platform stability and drag-free performance
Mendes, L.; Russano, G.; Lloro, I. +76 more
The science operations of the LISA Pathfinder mission have demonstrated the feasibility of sub-femto-g free fall of macroscopic test masses necessary to build a gravitational wave observatory in space such as LISA. While the main focus of interest, i.e., the optical axis or the x -axis, has been extensively studied, it is also of great importance …
M I C R O S C O P E limits on the strength of a new force with comparisons to gravity and electromagnetism
Fayet, Pierre
Extremely weak new forces could lead to apparent violations of the equivalence principle. The MICROSCOPE experiment implies that the relative strength of a new long-range force, compared with gravity, is constrained to |α¯ g|<3.2 ×10-11 , 2.3 ×10-13 , 2.2 ×10-13 , 6.7 ×10-13 , and 1.5 ×10
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…