If all the information about the universe is stored on some 2-dimensional boundary, why is a 3-dimensional "hologram" of the information needed? Certainly as the good Mr. William Ocam of Orange tells us, quite sensibly I think, "entities ought not be multiplied beyond necessity," so I doubt he would consider 3-dimensional re-representation of the data to be needed or warranted.
We know that one can represent, at least in principle, even an infinite amount of 2-dimensionally arrayed information in a 3-dimensional space. And it certainly seems just as likely that an infinite 3-dimensional data bank can also be stored on a 2-dimensional surface; it's the peculiarities of "infinite sets" that makes it possible. And of course, the information from the 3-dimensional virtual world we are supposedly living in could also be stored in even just a (very long) 1-dimensional world, à la Cantor's astounding "I see it but I can't believe it revelation."
So then, if one, as demiurge, wants to have a maximally nice and tidy universe, why not just store all the data, for however many dimensions you might want to have in your world, in one dimension, and then have a very fast Turing Machine, -- why maybe even a couple, three of them, -- to calculate everything that "happens" from the big bang to the great rip?
And, by the way, does the 2-dimensional, all-information-holding, boundary, if it exists, exist inside or outside of the 3-dimensional "virtual" universe itself? If it is inside, then surely it too has a "correlate" in some other 2-space, and one which is not just a subset of itself, and thus then also another subset of itself, ad infinitum? And if, on the contrary, the boundary is actually outside the universe, well then, where is it?
Hmm, didn't those smart old Greeks worry about that kind of thing about 2,500 years ago? What has it got to do with physics in our 21st century world other than to provide a truly ad hoc "solution" to the old quantum information paradox? I think the whole holographic universe theory, however well accepted, and even useful as it may be, really needs to confront some very basic metaphysical problems.
Perhaps it has. If so, I've never seen the discussions. Any pointer?