How gravitational potential effects mass? Is this formula m = m0/sqrt(1-Φ/c^2) right or at least close to reality? The purpose of the question: If overage Φ decreases because of Universe is expanding, then maybe it can help to find another explanation why it expands with acceleration. Lets consider small particle with momentum p = m*v. If this small mass m decrease because of decreasing of overage Φ of whole visible Universe, then because of momentum conservation law v must arise. So it would generate expanding with acceleration. Maybe this would help to explain things without dark energy, or at least would change predicted amount of it?