About me

I am a PhD student in cosmology and astrophysics, working at the Institut d'Astrophysique Spatiale in Orsay, France, in the COSM!X group.

My interest in cosmology is on understanding the invisible mass called dark matter and the unknown fluid called dark energy.
My work is focused on combining different observations of the distribution of matter, like the CMB weak lensing and the distribution of galaxies. Combining them allows to raise degeneracies between cosmological parameters, and to lower systematic uncertainties which are specific to each probes.
I am also interested in understanding the relations between the dark matter and the baryons, and how galaxies and clusters of galaxies formed and evolved in the gravitational potential well formed by dark matter.


  • The COSMOS-UltraVISTA stellar-to-halo mass relationship: new insights on galaxy formation efficiency out to z∼5.
    L. Legrand, H.J. McCracken, I. Davidzon, O. Ilbert, J. Coupon, N. Aghanim, M. Douspis, P. L. Capak, O. Le Fèvre, B. Milvang-Jensen
    We trace the evolution of the stellar mass to halo mass ratio of galaxies up to z=5 thanks to exquisite mass and photometric redshift in the COSMOS-UltraVISTA field. We found that the peak of this ratio increases with redshift, pointing to a scenario where cold gas inflows become progressively more important in driving star-formation at very high redshifts.

Talks in conferences