Speaker
Description
Our well-established gravity model, the theory of general relativity, has been extensively tested in strong-field regimes. However, no observational test has yet confirmed its validity on cosmological scales, where the universe’s dark components are necessary to fit LSS data. The detection of large-scale relativistic effects via galaxy power spectrum measurements would provide such an unprecedented confirmation. Amongst these relativistic contributions, the Doppler term acts as an imaginary correction in the relation between the galaxy density contrast and that of matter, and mostly affects the large scales usually plagued by cosmic variance. Also, it is sample-dependent, thus different galaxy populations display different contributions in their power spectra. In the search for the optimal galaxy samples to achieve a detection of the relativistic term, we can split a galaxy population according to luminosity, and then perform a multi-tracer analysis with auto-correlations of the sub-samples and their cross-power spectrum. I will be talking about how to make it possible a first detection of the relativistic Doppler signal, with data from ongoing galaxy surveys, such as Euclid and DESI, using this single-dataset, multi-tracer approach.
| Other topic / keywords: | Galaxy clustering, multi-tracer, cross-correlations, tests of gravity, general relativity |
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