Anisotropy of tile Hubble constant in a cosmological model with a local void on scales of similar to 200 Mpc

摘要

A spherical cosmological model with a local void on scales of similar to 200 Mpc and with an inhomogeneous Hubble constant was proposed in two recent papers. This model explains consistently the observed properties of the cosmic bulk flow, the accelerating behavior of type Ia supernovae and the CMB dipole anisotropy without invoking a cosmological constant. To an observer in a position deviated from the center, the anisotropy of the Hubble constant appears owing to the directional dependence of the distance from the observer to the boundary of the void region. It is found that the anisotropy is maximally about 6 % of the constant in the region 200 similar to 500 Mpc from the observer. This inhomogeneity and anisotropy of the Hubble constant are not so large as to be inconsistent with the present observation. The detection of this anisotropy will be useful to clarify the implication of the inhomogeneity of the Hubble constant. [References: 27]