Seminarium Zakładu Astrofizyki i Kosmologii
- Data: poniedziałek, 18 listopada 2013
- Godzina: 10.15
- Temat: "A possible resolution of tension between Planck and Type Ia supernova observations"
- Prelegent: Dr Zhengxiang Li, Beijing Normal University, China
- Adres: sala 357, Bankowa 14 (u teoretyków)
- Streszczenie: There is an obvious tension between cosmological parameters obtained from Planck cosmic microwave background radiation observations and that derived from the observed magnitude-redshift relation for the type Ia supernova (SNe Ia). Here, we show that the tension can be alleviated, if we first calibrate, with the help of the distance-duality relation, the light-curve fitting parameters in the distance estimation in SNe Ia observations with the angular diameter distance data of the galaxy clusters and then re-estimate the distances for the SNe Ia with the corrected fitting parameters and explore their cosmological implications in the context of the spatially flat cosmology. We finnd a higher value for the matter density parameter, Omega_m, as compared to that from the original SNLS3, which is in agreement with Planck observations at 68.3% confidence. Therefore, the tension between Planck measurements and SNe Ia observations regarding Omega_m can be effectively alleviated without invoking new physics or resorting to extensions for the standard concordance model. Moreover, with the absolute magnitude of a fiducial SNe Ia, M, determined first, we can also obtain a constraint on the Hubble constant with SNLS3 alone, which is also consistent with Planck.