border of the universe

              Explaining the lens effect was done by curving space but also using the principle of least action: A photon passing mass seeks a route with as big steps (lower frequency) and a minimum of these. Observed is not a route close to the mass and in the book The Quantum Theory of Gravitation therefore the conclusion is drawn (Vasily Yanchilin) that near mass frequencies are higher or in old wording: time there passes speedier. Modern way of saying is that since Creation everywhere in the universe a same amount of time has passed but clocks differ because they are bound to the local gravitation potential. This regards also atomic clocks which have less ticks on Earth than in space and therefore need correction of what is indicated. Research on this topic may consider that g is a scalair and changes linear, while the involved energy for jumping electrons involves 3 spatial dimensions for creating the new orbit; thus in simple words: the atom gets bigger far from mass and electron transitions becom easier with more ticking. 

Note that fast process in the Beginning at a very young conentrated universe is generally accepted and stillstand of time in a so called black hole does not correspond. These things may be remnants or new forming of the stuff existing before the universe became transparant. The published photograph of a black hole was just a construction with an opening in the hot surroundings to let us see it. The validity of the special theory of relativity can be understood thus that there is a relation between c and the gravitational potential. The latter is in all directions the same and so also c, but both change according different time and place (Yanchilin). To avoid inflation, which is not really explainable in physics, a new model of the universe may be built on change of c from very high in the early days of the universe to zero at its shifting border. If no energy is lost the "mass" of photons  increases there and attraction in opposite direction may occur. That in some way might render the centimeter radiation from the "background", making inflation superfluous.