The physics kind of hologram, not the Star Trek kind. Sorry!
I generally find physics super interesting, even though I barely understand any of it. To be fair, I'm not alone, a lot more in modern physics is an enormous question mark than most people realize. We basically have no idea what's going on.
Quantum gravity is a complex beast; gravity turns out to be super weird in all sorts of ways and we (that is, man very very smart people) haven't figured out yet how to combine quantum theory and gravity.
This new paper is based on the holographic principle (no, not the Epica Album although it's pretty good. Go listen to it!) and therefore based on String Theory. That's super deep into "no fucking clue" territory.
Anyways, I still think it's a cool idea!