Status of Hawking Hartle no boundary proposal

[Naty1]

I came across this statement from James Hartle on Stephen Hawking's website,

http://www.hawking.org.uk/


and wondered where you see this proposal currrently [Hartle sure seems to think it explains an awful lot] :

James Hartle:

...Today, more than 25 years after its proposal, the no-boundary state has successfully explained the origin of classical spacetime, the origin of the detailed structure of the universe seen in the distribution of galaxies, and the arrows of time of the universe. Stephen, Thomas Hertog, and I are continuing to work to see how far the no boundary
quantum state can go in explaining our quantum universe."

Wikipedia has a brief discussion here:
Hartle–Hawking state
http://en.wikipedia.org/wiki/Hartle–Hawking_state

which explains that

...the theory is a quantum gravity proposal concerning the state of the universe prior to the Planck epoch... that there was no time before the Big Bang because time did not exist before the formation of spacetime associated with the Big Bang...that if we could travel backward in time ... time gives way to space such that at first there is only space and no time... According to ... Hartle-Hawking [the] universe has no beginning... it simply has no initial boundaries in time nor space...According to the theory time diverged from three state dimension - as we know the time now - after the Universe was at the age of the Planck time.[1]

If there are updates in ARXIV I'd be interested in a few you experts consider worthwhile...I could not find anything, but that's likely a reflection of my lack of search skills...

Are there any 'competing theories' where time emerges before space...or other entities come first, say, gravity...??

 

[Naty1]

So nobody's come with a different view than space emerges before time??

If so, not such a good commentary on the last 25 years of quantum theory.

 

[sheaf]

I'm struggling to remember, but doesn't the HH proposal result in an expanding universe with closed spatial 3-slices? That's problematic given that cosmological measurements suggest that our universe is spatially open (just!). If I recall correctly there's no obvious way to modify the mechanism to produce the open case.

Note: this is really a beyond standard model topic - you might get some more informed opinions if you post it there.

 

[Naty1]

Here's an excerpt from an article by Sean Carroll which seems to directly conflict with the much older theory of Hawking Hartle:

The first possibility is that the quantum state of the universe really does evolve in time — i.e. that the Hamiltonian is not zero, it truly does push the state forward in time. This seems like the generic case (there are more ways to be not-zero than to be zero), and it’s certainly the one that we spend time considering in introductory courses when we foist quantum mechanics on fearful undergraduates for the first time. A wonderful and under-appreciated consequence of quantum mechanics is that, if this possibility is right (the universe truly evolves), time cannot truly begin or end — it goes on forever. Very unlike classical mechanics, where the universe’s trajectory through the space of states can bring it smack up against a singularity, at which point time presumably ceases. In QM, every state is just as good as every other state, and the evolution will go happily marching along.

and then explains the Hawking Hartle view:
" The other possibility is that the universe doesn’t evolve at all — the Hamiltonian is zero, and there is some space of possible states, but we just sit there, without a fundamental “passage of time.” ...quantum cosmologists like James Hartle, Stephen Hawking, Alex Vilenkin, Andrei Linde and others have in mind when they are talking about the “creation of the universe from nothing.” In this kind of picture, there is literally a moment in the history of the universe prior to which there weren’t any other moments. There is a boundary of time (presumably at the Big Bang), prior to which there was … nothing. No stuff, not even a quantum wave function; there was no prior thing, because there is no sensible notion of “prior.”

http://blogs.discovermagazine.com/cosmicvariance/2012/04/28/a-universe-from-nothing/

And so that seems to answer my question: The Hawking Hartle view is still one possibility.