P. Delva
University of Paris
Atomic Clock Ensemble in SpacePhysicsGravitationAstronomyGeodesyGravitational fieldGeneral relativityOrbitDark matterGeopotentialGravity Probe AGravitational redshiftSatelliteOptical fiberAtomic clockRange (statistics)Time and frequency transferComputational physicsComputer scienceRemote sensing
Publications 18
#1Marc Lilley (University of Paris)H-Index: 3
#2Etienne Savalle (University of Paris)H-Index: 5
Last. Peter Wolf (University of Paris)H-Index: 22
view all 8 authors...
The Atomic Clock Ensemble in Space is a fundamental physics mission of the European Space Agency to be launched in August 2021. It relies on a high-performance clock onboard the International Space Station (ISS), a network of high-performance clocks on ground, a dedicated 2-way microwave link (MWL) enabling space-to-ground and ground-to-ground clock comparisons, as well as an optical link (ELT). PHARAO/SHM (Projet d’Horloge Atomique par Refroidissement d’Atomes en Orbite/Space Hydrogen Maser), t...
#2P. DelvaH-Index: 8
#3Ali Al-MasoudiH-Index: 13
Last. Peter WolfH-Index: 22
view all 54 authors...
We search for transient variations of the fine structure constant using data from a European network of fiber-linked optical atomic clocks. By searching for coherent variations in the recorded clock frequency comparisons across the network, we significantly improve the constraints on transient variations of the fine structure constant. For example, we constrain the variation to |δα/α| ~10^4 km) objects.
#1Luigi Cacciapuoti (ESA: European Space Agency)H-Index: 25
#2Michele Armano (ESA: European Space Agency)H-Index: 16
Last. Francois Xavier EsnaultH-Index: 1
view all 29 authors...
Atomic Clock Ensemble in Space (ACES) is a mission designed to test Einstein’s theory of General Relativity from the International Space Station (ISS). A primary frequency standard based on laser cooled caesium atoms (PHARAO) and an active H-maser (SHM) generate a clock signal that is distributed to a network of clocks on the ground to perform space-to-ground comparison. With a fractional frequency stability of 1 × 10−16 after 10 days of integration time and an accuracy of 1 – 2 × 10−16 , ACES w...
#1F. RiedelH-Index: 3
#2Ali Al-MasoudiH-Index: 13
Last. Ch. LisdatH-Index: 7
view all 49 authors...
We carried out a 26-day comparison of five simultaneously operated optical clocks and six atomic fountain clocks located at INRIM, LNE-SYRTE, NPL and PTB by using two satellite-based frequency comparison techniques: broadband Two-Way Satellite Time and Frequency Transfer (TWSTFT) and Global Positioning System Precise Point Positioning (GPS PPP). With an enhanced statistical analysis procedure taking into account correlations and gaps in the measurement data, combined overall uncertainties in the...
#2P. Delva (University of Paris)H-Index: 8
#3Olivier Lopez (University of Paris)H-Index: 27
Last. Paul-Eric Pottie (University of Paris)H-Index: 20
view all 5 authors...
We present a study of the fundamental limit of fiber links using dedicated link architecture. We use an experimental arrangement that enables us to detect the forward and backward propagation noise independently and simultaneously in optical fiber and where the optical phase evolution is expected to be driven by the only contribution of the reference arms of the Michelson interferometer ensemble. In this article, we demonstrate indeed the high correlation between the optical phase evolution and ...
#1Hélène Pihan-Le Bars (University of Paris)H-Index: 2
#2C. Guerlin (Collège de France)H-Index: 4
Last. Peter Wolf (University of Paris)H-Index: 22
view all 14 authors...
We use data from the T-SAGE instrument on board the MICROSCOPE space mission to search for Lorentz violation in matter-gravity couplings as described by the Lorentz violating Standard-Model Extension (SME) coefficients (\bar{a}_\text{eff})_\mu^w where (\mu = T,X,Y,Z and (w = e,p,n for the electron, proton and neutron. One of the phenomenological consequences of a non-zero value of those coefficients is that test bodies of different composition fall differently in an external gravitation...
#1Guillaume LionH-Index: 4
#2Isabelle PanetH-Index: 18
Last. P. DelvaH-Index: 8
view all 4 authors...
#1Etienne Savalle (University of Paris)H-Index: 5
#2C. Guerlin (Collège de France)H-Index: 4
Last. Peter Wolf (University of Paris)H-Index: 22
view all 6 authors...
We investigate the performance of the upcoming ACES (Atomic Clock Ensemble in Space) space mission in terms of its primary scientific objective, the test of the gravitational redshift. Whilst the ultimate performance of that test is determined by the systematic uncertainty of the on-board clock at 2-3 ppm, we determine whether, and under which conditions, that limit can be reached in the presence of colored realistic noise, data gaps and orbit determination uncertainties. To do so we have develo...
Abstract We present the result of the analysis of the GREAT (Galileo gravitational Redshift test with Eccentric sATellites) experiment. An elliptic orbit induces a periodic modulation of the fractional frequency difference between a ground clock and the satellite clock, partly due to the gravitational redshift, while the good stability of Galileo clocks allows one to test this periodic modulation to a high level of accuracy. GSAT0201 and GSAT0202, with their large eccentricity and on-board H-mas...
#1P. Delva (University of Paris)H-Index: 8
#2Heiner Denker (Leibniz University of Hanover)H-Index: 19
Last. Guillaume Lion (Sorbonne)H-Index: 4
view all 3 authors...
The theory of general relativity was born more than one hundred years ago, and since the beginning has striking prediction success. The gravitational redshift effect discovered by Einstein must be taken into account when comparing the frequencies of distant clocks. However, instead of using our knowledge of the Earth’s gravitational field to predict frequency shifts between distant clocks, one can revert the problem and ask if the measurement of frequency shifts between distant clocks can improv...
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