Hubble time dilation

The Hubble time dilation is an effect of accumulation of time dilation with distance from observer so for small distances it looks roughly propotional to the distance. The exact effect is <math>d\tau/dt=exp(-r/R_s)</math>, where <math>\tau</math> is proper time at point in deep space, <math>t</math> is coordinate time of the point, <math>r</math> is distance to this point from observer, and <math>R_s</math> is radius of curvature of space (called by cosmologists "Einstein's radius").