XY Plane with Z as Time: Big Bang?

[sloughter]

Shortly after the Big Bang was there an extremely brief period of time when the universe consisted of an xy plane with z as time, the third dimension? In other words did a three dimensional universe predate a four dimensional universe?

 

[PAllen]

Shortly after the Big Bang was there an extremely brief period of time when the universe consisted of an xy plane with z as time, the third dimension? In other words did a three dimensional universe predate a four dimensional universe?

Do you have any reference for this idea?

There is a concept (especially pursued by Professor Steven Carlip) that at very short scales (Planck length), the number of dimensions decreases (spontaneous dimension reduction). However, I have no idea of this is what you are referring to. Also, z is just a letter of the alphabet. If z functions as time, you might as well call it t (or Bob for that matter; it doesn't matter what you call it).

 

[sloughter]

No--I do not have a reference for that idea. Yes---that is what I meant about the third dimension being time. I was not familiar with the work of Professor Steven Carlip and can only speculate that these dimensions may even be shorter than the Planck length.

 

[Bill_K]

There is a concept (especially pursued by Professor Steven Carlip) that at very short scales (Planck length), the number of dimensions decreases (spontaneous dimension reduction).

I know that Carlip has worked on 2+1-dimensional gravity as a simple model for both classical and quantum gravity, but I can't find any mention that he thinks it has any connection to reality, even at the Planck scale.

 

[PAllen]

I know that Carlip has worked on 2+1-dimensional gravity as a simple model for both classical and quantum gravity, but I can't find any mention that he thinks it has any connection to reality, even at the Planck scale.

I am referring to a more recent line of his work. See:

http://arxiv.org/abs/1108.4686
http://arxiv.org/abs/1207.4503
[edit: more on this line of research]
http://arxiv.org/abs/1009.1136
http://arxiv.org/abs/1103.5993
http://arxiv.org/abs/0909.3329