It is assumed that in a reasonable approximation we live inside a blackhole. Hawking temperature (quantal notion) is deduced from the mass of the Universe. After this Unruh formula expressing the temperature of the radiation observed from a system in an accelarating motion is used. Also this formula is quantal. Usually the temperature is deduced from acceleration but now acceleration is deduced from temperature using existing formula so that one goes outside the original context. The assignment of this acceleration with the growth of the radius of the blackhole is second step out-of-context. The third step out-of-context is the identification of the acceleration-essentially given by Hubble constant- as the acceleration of the cosmic expansion. The outcome happens to be consistent with observations.
One can forget the steps leading to the conclusion and notice that the acceleration for purely dimensional reasons is apart from a numerical constant equal to Hubble constant unless one is willing to bring in some genuinely new physics. That the acceleration is proportional to Hubble constant is what should be the starting point since it suggests that the solution of the negative energy puzzle might be "kinematical" in some sense. Despite all of these out-of-contexts I see the emergence of this kind of papers as a positive sign. Theoretical physics is gradually beginning to recover from the social pressures of super string ideology and problem centered approach is beginning to become in fashion again.
This numerical co-incidence could reflect something deeper. What might be essential is that space-time is replaced with a finite region of it: now it is the interior of a black hole in order to get the 3-D surface and the familiar formulas to get numbers which we so much appreciate. Blackhole as such need not be essential. Holography is something respectable but fuzzy enough to justify the adhoc identification of Unruh acceleration reproducing the Hawking temperature as the acceleration for the expansion of the Universe.
In TGD framework space-time surface is replaced with many-sheeted space-time so that one obtains effective boundaries: effective they correspond to pairs of wormhole throats and inside wormhole throats the induced metric is Euclidian. Also holography is key element of TGD. "Partonic" 2-surfaces plus their 4-D tangent space distributions at partonic 2-surfaces code for the information about the physical states in zero energy ontology. The motivation for the "partonic" is that also elementary particles correspond to this kind of 2-surfaces -very tiny in this case.
In TGD inspired quantum cosmology the continuous cosmic expansion is replaced with a sequence of short periods of accelerating expansion followed by longer periods during which a given space-time sheet does not expand. There is a fractal hierarchy of cosmologies within cosmologies. By criticality the period of the accelerated expansion obeys a universal dynamics. The mere condition that 3-space is flat (criticality tolerates no dimensional parameters) and imbeddable to M4×CP2 fixes the Robertson-Walker metric apart from a parameter telling the duration of the expansion period. The duration is necessarily finite for both critical and over-critical cosmology. Accelerated expansion is due to a negative "pressure" and implied by the sub-manifold constraint so that there is no need for mysterious particles with negative kinetic energy nor for cosmological term. This gives a meaning for the "kinematic". Sub-manifold constraint solves the same basic problems of standard cosmology as inflation in terms of flatness of 3-space but avoids the inflation of inflations plaguing the inflationary scenario. It also explains all standard model quantum numbers and leads to a highly predictive scenario for new physics effects. This adds a further meaning to the "kinematic".
While writing this I realized that for more than two decades I have tried to tell about this beautiful solution to the colleagues but in vain! Tells something about the deph of the intellectual abyss in theoretical physics. People waste their time to long discussions about ad hoc dimensional analysis tricks by old names interpreting old formulas outside their original context instead of seeing the trouble of learning something genuinely new. It is so safe and so much easier than trying to understand long arguments leading to completely new formulas!