Humboldt-Universität zu Berlin - Mathematisch-Naturwissen­schaft­liche Fakultät - Institut für Physik

Institutskolloquium: Prof. Subir Sakar (University of Oxford) spricht zu:

A challenge to the cosmological standard model

Abstract

In the ΛCDM cosmological model the Universe is assumed to be isotropic & homogeneous when averaged on large scales. That the CMB has a dipole anisotropy is interpreted as due to our peculiar (non-Hubble) motion because of local inhomogeneity. There must then be a corresponding dipole in the sky distribution of sources at high redshift. Using catalogues of radio sources & quasars we find that this expectation is rejected at >5σ, i.e. the distribution of distant matter is not isotropic in the 'CMB frame’. This calls into question the standard practice of boosting to this frame to analyse cosmological data, in particular to infer acceleration of the Hubble expansion rate using Type Ia supernovae, which is interpreted as due to a Cosmological Constant Λ.

Das Kolloquium wird "hybrid" durchgeführt, kann also sowohl im Hörsaal als auch über zoom verfolgt werden.

Zoom Link:
https://hu-berlin.zoom.us/j/64567336962?pwd=QjhyMW5SbFVBZWVNRWJrTFBFN2Rtdz09
Meeting-ID: 645 6733 6962
Passwort: 607723