Scientifically calculating the maximum radius of the universe using the energy of photons

The energy of photons is mc ^ 2, and the potential energy of photons at the edge of the universe is only gravitational potential energy. The energy of a photon is the sum of kinetic energy: mc ^ 2=mc ^ 2/2+mgR, that is, mgR=mc ^ 2/2. G is the gravitational constant of the universe, and R is the final radius of the universe. The transformation of the universe is a process of mass and energy transformation. According to Einstein's mass energy equation E=mc ^ 2, when the mass loss of the universe is half of the mass at the beginning of the universe, the remaining mass of the universe must also move at the speed of light, and the mass of the universe is not changing. The current mass of the universe is about the order of 10 ^ 53kg. Let's assume that the mass at the beginning of the universe is: M=2 × 10 ^ 53kg, m=M/2. A photon at the edge of the universe must have: mgR=mc ^ 2/2, simplified as R=c ^ 2/2g - (1), according to the law of universal gravitation g=MG/2R ^ 2- (2), G is the constant of universal gravitation, and the simultaneous equations (1) and (2) solve for R=MG/c ^ 2=1.48 × 10 ^ 26 meters. Conclusion: The final radius of the universe is equal to the product of the mass at the beginning of the universe multiplied by the gravitational constant and then divided by the square of the speed of light.