Graduate Questions: Gott-Li Can a Universe Create Itself?

[AntHak]

Hello, this is my first post here. I have a couple questions regarding the Gott-Li model of a self creating universe, proposed in "Can the Universe Create Itself?", Phys. Rev. D 58, (1998).

https://doi.org/10.48550/arXiv.astro-ph/9712344

First, I should disclose that I am an amateur and may hold some misconceptions. I tried to keep these questions based in science but, recognize that some may border philosophical, I hope they are valid nonetheless.

1. I was under the impression that the laws of physics would be emergent in this model, but the author's closing statement "Do the laws of physics prevent the Universe from being its own mother?" confuses me. Does this suggest the laws of physics governed the existence of the initial Universe/CTC?

2. If a CTC caused our inflationary Universe/Multiverse, couldn't this have happened more than once (i.e. multiple/infinite CTCs creating their own inflationary multiverses separate from our own)?

3. To what extent is the Universe created from nothing in this model? Would the initial CTC be a "brute fact", or room for "turtles" farther down?

Thank you for any answers!

 

[Drakkith]

1. I was under the impression that the laws of physics would be emergent in this model, but the author's closing statement "Do the laws of physics prevent the Universe from being its own mother?" confuses me. Does this suggest the laws of physics governed the existence of the initial Universe/CTC?

The entire paper is based on the idea of a 'closed timelike curve', which is a particular solution to the equations of general relativity. This would seem to require that the laws of physics, at least for GR, exist outside or separate of the universe in some sense.

3. To what extent is the Universe created from nothing in this model? Would the initial CTC be a "brute fact", or room for "turtles" farther down?

In my view there doesn't seem to be any creation event in this model. If we follow a worldline through the CTC it simply comes back around to its original starting point. There's no point at which beyond this point the universe doesn't exist.

 

[AntHak]

The entire paper is based on the idea of a 'closed timelike curve', which is a particular solution to the equations of general relativity. This would seem to require that the laws of physics, at least for GR, exist outside or separate of the universe in some sense.In my view there doesn't seem to be any creation event in this model. If we follow a worldline through the CTC it simply comes back around to its original starting point. There's no point at which beyond this point the universe doesn't exist.

Thanks for explaining Drakkith!

J. Richard Gott also has a few interviews and lectures explaining further available on YouTube; I believe he said a CTC could explain the first cause problem (the Universe essentially caused itself). However, I agree with your interpretation, I don't see any creation event in this model.