PeterDonis's latest activity

It's a theorem about spacetime models using General Relativity. Such models can include stress-energy that has an equation of state that...

Can you revert to a previous version that is known not to have this problem?

I've already explained that: anything with an equation of state ##p = w \rho## where ##w < −1/3## violates the energy conditions that...

Not exactly. ##w## is the ratio of pressure to density. For the simplest model of inflation (which works just like a cosmological...

https://www.physicsforums.com/forums/sci-fi-writing-and-world-building.220/ :wink:

That shouldn't be possible with a cosmological constant, because the energy density of matter and radiation can only decrease with...

Who said the superposition had to be equal?

Thanks, that makes it much clearer what experiment you're talking about. Unfortunately, your OP doesn't really give a good description...

Where? Please give a reference.

No worries, post as you can. I hope you feel better soon.

Yes. Not "never". Just not in the last two billion years. Inflation does cause accelerated expansion, yes. In our best current model...

For reference, this paper looks like it has a good discussion of the 1965 Penrose singularity theorem: https://arxiv.org/abs/1410.5226

Sort of. It can apply to an expanding universe that is only dark energy dominated after a certain time, but not before that. That is...

The "Einstein's equations hold" part is "general relativity is valid". The "zero or negative cosmological constant" is part of the...

As far as I know, Hawking and Penrose didn't publish any papers together prior to the 1970 paper. Penrose published a paper in 1965...