Study of the anisotropy of cosmic expansion on ZTF type Ia supernovae simulations

par Chloé Barjou-Delayre

vendredi 28 nov. 2025, 14:30 → 15:30 Europe/Paris

9109

The cosmological principle assumes the isotropy of the Universe at large scales. Recent disagreements with the standard model give legitimacy to investigate the possibility of anisotropy in the Universe. The high coverage of the Zwicky Transient Facility survey (ZTF) allows us to carry out a study of the veracity of this principle by using observations of type Ia supernovae (SNe Ia). This unique low redshift (z<0.15) survey with more than 3000 SNe Ia in the second data release (ZTF-DR2-SNe Ia) increases by a factor 10 the current low-redshift statistics. Its sky coverage, which represents more than the Northern sky, allows to develop new cosmological analysis such as the study a possible anisotropy of the cosmic expansion. I will present a method for a measurement of anisotropy in the Hubble constant H0. This method is build to recover an introduced dipole in realistic simulations of the ZTF-DR2-SNe Ia.