Search Publications
MICROSCOPE Mission: First Results of a Space Test of the Equivalence Principle
Chhun, Ratana; Métris, Gilles; Rodrigues, Manuel +40 more
According to the weak equivalence principle, all bodies should fall at the same rate in a gravitational field. The MICROSCOPE satellite, launched in April 2016, aims to test its validity at the 10-15 precision level, by measuring the force required to maintain two test masses (of titanium and platinum alloys) exactly in the same orbit. …
Possible Dark Matter Annihilation Signal in the AMS-02 Antiproton Data
Yuan, Qiang; Fan, Yi-Zhong; Tsai, Yue-Lin Sming +1 more
Using the latest AMS-02 cosmic-ray antiproton flux data, we search for a potential dark matter annihilation signal. The background parameters about the propagation, source injection, and solar modulation are not assumed a priori but based on the results inferred from the recent B / C ratio and proton data measurements instead. The possible dark ma…
No Evidence for Extensions to the Standard Cosmological Model
Sellentin, Elena; Heavens, Alan; Hosenie, Zafiirah +4 more
We compute the Bayesian evidence for models considered in the main analysis of Planck cosmic microwave background data. By utilizing carefully defined nearest-neighbor distances in parameter space, we reuse the Monte Carlo Markov chains already produced for parameter inference to compute Bayes factors B for many different model-data set combinatio…
Astrometric Search Method for Individually Resolvable Gravitational Wave Sources with Gaia
Gilmore, Gerard; Mihaylov, Deyan P.; Moore, Christopher J. +1 more
Gravitational waves (GWs) cause the apparent position of distant stars to oscillate with a characteristic pattern on the sky. Astrometric measurements (e.g., those made by Gaia) provide a new way to search for GWs. The main difficulty facing such a search is the large size of the data set; Gaia observes more than one billion stars. In this Letter …
Turbulent Kinetic Energy in the Energy Balance of a Solar Flare
Harra, L. K.; Kontar, E. P.; Perez, J. E. +5 more
The energy released in solar flares derives from a reconfiguration of magnetic fields to a lower energy state, and is manifested in several forms, including bulk kinetic energy of the coronal mass ejection, acceleration of electrons and ions, and enhanced thermal energy that is ultimately radiated away across the electromagnetic spectrum from opti…
Charge-Induced Force Noise on Free-Falling Test Masses: Results from LISA Pathfinder
Mendes, L.; Madden, S.; Russano, G. +93 more
We report on electrostatic measurements made on board the European Space Agency mission LISA Pathfinder. Detailed measurements of the charge-induced electrostatic forces exerted on free-falling test masses (TMs) inside the capacitive gravitational reference sensor are the first made in a relevant environment for a space-based gravitational wave de…
Electron and Ion Dynamics of the Solar Wind Interaction with a Weakly Outgassing Comet
Henri, Pierre; Divin, Andrey; Deca, Jan +4 more
Using a 3D fully kinetic approach, we disentangle and explain the ion and electron dynamics of the solar wind interaction with a weakly outgassing comet. We show that, to first order, the dynamical interaction is representative of a four-fluid coupled system. We self-consistently simulate and identify the origin of the warm and suprathermal electr…
From Planck Data to Planck Era: Observational Tests of Holographic Cosmology
Afshordi, Niayesh; Corianò, Claudio; Delle Rose, Luigi +2 more
We test a class of holographic models for the very early Universe against cosmological observations and find that they are competitive to the standard cold dark matter model with a cosmological constant (Λ CDM ) of cosmology. These models are based on three-dimensional perturbative superrenormalizable quantum field theory (QFT), and, while they pr…
Measurement of a Cosmographic Distance Ratio with Galaxy and Cosmic Microwave Background Lensing
Madhavacheril, Mathew S.; Miyatake, Hironao; Spergel, David N. +4 more
We measure the gravitational lensing shear signal around dark matter halos hosting constant mass galaxies using light sources at z ∼1 (background galaxies) and at the surface of last scattering at z ∼1100 (the cosmic microwave background). The galaxy shear measurement uses data from the CFHTLenS survey, and the microwave background shear measureme…