Einstein's radius of universe

Einstein's radius of universe, usually denoted in cosmology by <math>R_E</math>, is the radius of curvature of space of Einstein's universe.

The exact length of Einstein's radius of universe is <math>R_E=c/\sqrt{4\pi G \rho}</math>, where <math>c</math> is speed of light in vavcuum, <math>G</math> is Newtonian gravitational constant, and <math>\rho</math> is density of space.

Assuming that we live in stationary (neither expanding nor contracting) Einstein's universe in which the Hubble constant is ca. <math>H_o=70km/s/Mpc</math> as established by observations, the Einstein's radius of universe is ca. 13 bilion light years. The exact number is then <math>R_E=c/H_o</math>.