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Reference : UMR8630-PACDEL-001
Workplace : PARIS 14
Date of publication : Tuesday, January 07, 2020
Type of Contract : FTC Scientist
Contract Period : 12 months
Expected date of employment : 1 March 2020
Proportion of work : Full time
Remuneration : Between 2695€ et 4 290 euros bruts/month depending on expertise.
Desired level of education : 5-year university degree
Experience required : Indifferent
Several astrophysical observations suggest that ordinary matter contributes only to around 5% to the total energy content of our Universe. The unknown remaining part has never been directly detected so far and is commonly separated into two components: dark matter which behaves as a pressure-less fluid and dark energy, a fluid exerting negative pressure. Many hypotheses have been imagined to explain these two components ranging from the introduction of a new type of matter to a modification of general relativity. Currently, all we know about dark matter is based on the gravitational interaction between the dark and luminous matter. Some theoretical models suggest that dark matter consists of ultralight transient topological defects that are regularly crossing the Earth [see e.g. https://arxiv.org/abs/1907.02661]. Such transients will produce signatures on both the GNSS atomic clocks and on the propagation of the GNSS electromagnetic signal. The goal of this project is to develop a modelling of GNSS observables including these possible signatures from Dark Matter transients and to develop a new strategy to analyse GNSS measurements to search for such Dark Matter candidates.
First, we will identify the best strategy to search for Dark Matter transients using the Galileo constellation. Then, we will develop a methodology and the associated tools to perform the first search for Dark Matter using Galileo measurements, which will be carried out using Galileo data and support from ESA (European Space Agency) and international laser ranging stations (ILRS - International Laser Ranging Service). The activity will benefit from experience gained by our team in analysing Galileo data for tests of general relativity [Delva et al. PRL 121, 231101, 2018].
Strong skills in statistics, data analysis and numerical computation are necessary. A good knowledge of GNSS data analysis will be favored. Theoretical knowledge of Dark Matter models is a plus.
SYRTE is one of the world's leading laboratories in the field of metrology, primary time and frequency standards and interferometry with cold atoms. The laboratory develops atomic clocks and state-of-the-art inertial sensors, limited by quantum projection noise. The "Theory and Metrology" team successfully led the GREAT (Galileo gravitational Redshift Experiment with eccentric sATellites) experiment, an ESA project that led to the current best test of gravitational redshift, improving the previous constraint by one order of magnitude. In addition, SYRTE has a lot of experience in fundamental physics tests and dark matter research, particularly related to atomic clocks and time and frequency transfer. This experience includes theoretical modeling, statistical analysis of large datasets, and new laboratory experiments. We have published numerous articles related to the EEP (Einstein Equivalence Principle), GR (General Relativity) or DM (Dark Matter) research tests.
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