A radiating star in Einstein-Gauss-Bonnet gravity

We generate a radiating star in Einstein-Gauss-Bonnet (EGB) gravity for spacetime dimension N = 5 and a shear-free geometry. The temporal boundary condition contains curvature corrections from the Lovelock tensor and reduces to the general relativity limit. A detailed analysis of the model indicates that the temporal evolution of the star is qualitatively different from general relativity. Firstly, the phase plane analysis shows that the phase trajectories are less constrained due to the Gauss-Bonnet parameter. Secondly, separable metrics in EGB gravity imply that shear-free collapse generates anisotropic pressures; the corresponding isotropic configurations in general relativity cannot arise because of the EGB curvature corrections. Remarkably it is possible to find radiating models in pure EGB gravity which involve Lambert functions. The symmetries associated with the EGB boundary condition have a structure different from general relativity. The self-similar nature of general relativity is lost in pure EGB gravity. Consequently, radiating bodies in EGB gravity possess distinct geometrical and physical features.