Graduate Dasgupta et al., What is the alternative to a unique dS vacua?

[Fra]

I thought I would start a thread, as as spinoff to perhaps highlight and contemplate of that the ideas in the paper mitchell porter pointed to means.

I just started to sniff it.. and wrote in the other thread "How to fix Relativistic QM so it's consistent?"
Indeed fixing relativity and how to understnad equivalences, seems to be the central issue of the below paper.

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If you're interested, https://arxiv.org/abs/2511.03798 is the current minor sensation on string theory Twitter, a mammoth paper so overloaded with features that no one even knows if it makes sense. :-) But maybe it deserves a separate thread.

Huge paper, I havent ready it through fully but skimmed parts of it it seems to me, to be a step in the right direction.

One conceptualy summary (setting aside the rich string-technical details) attempt. Unless I misinterpret this (then please correct me), it seems the paper suggest the insight that general relativistic 4D spacetime structure should not be understood like an equivalence between views, but some alterantive construct with some internal tension in form om inconsistencies are unavoidable. This is why they consider it an emergent meta state (GS) instead. So seeking an old style vacuum is the wrong question.

Conceptually I think this is in the right direction. This really hits to the heart of the nature of one of the core constructing principle in traditional theories, and the nature of law that different observational perspectives must be equivalent - but this one solution, but I think not hte only one to the problem of no distiniguished observer. The paper considers sectors, but conceptaulyl I would associate a sectors to, perhaps not one obserever, but a subgroup of observational perspectives.

But I should read this more thouroughly, but it is extremely dense to extract the conceptual take away, from 500p technical paper without getting lost in detail. Technical detail is eventually critical, but so is conceptual understnading. both is somehow needed.

Perhaps a separate thread would be motived, but i havent digged deep enough in the paper yet.

/Fredrik

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Then i stumbled upon this youtube talk
Keshav Dasgupta: What if string theory has a de Sitter excited state?

Just in case someone else has something it say about it. I'm mainly interested in generalisations, and understnad if this really does suggest a turn in the constructing principles of the string theory program? In particular the view on equivalence classes, can we extend it even beyond spacetime perspectives, what about the internal spaces. Maybe I am jumping ahead of things, but it does seem to me, that this is a first step, towards a deeper reevaluation of some of the constructing principles? Perhaps in this threa, those more informed about string theory can comment. I see this interesting conceptually even beyond string theory.

Ps. I havent looked at the video myself yet, but will when i get time. but i thought i would post it. a youtube clip may be esaier to wade through than 500 pages.

/Fredrik

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[mitchell porter]

It turns out that the 500-page paper had a forerunner in 2000 that's just 100 pages, so it might be easier to read. :-)

"de Sitter Space as a Glauber-Sudarshan State" (Brahma, Dasgupta, Tatar)

This paper starts with a review of the De Sitter debate in quantum gravity and string theory.

The idea is: you can't have quantum De Sitter as a stable vacuum, and probably not even as a metastable vacuum, but maybe you can have it as an excited state on top of a stable Minkowski or Anti De Sitter vacuum.

It reminds me of how, in Samir Mathur's fuzzball paradigm for stringy black holes, an event horizon is an artefact of coarse-graining rather than an objective microphysical property (see question 7.7 in his fuzzball FAQ).

 

[Fra]

The idea is: you can't have quantum De Sitter as a stable vacuum, and probably not even as a metastable vacuum, but maybe you can have it as an excited state on top of a stable Minkowski or Anti De Sitter vacuum.

It reminds me of how, in Samir Mathur's fuzzball paradigm for stringy black holes, an event horizon is an artefact of coarse-graining rather than an objective microphysical property (see question 7.7 in his fuzzball FAQ).

The question is how far to take this. MY thinkking is that abandoning the dS vaccum, although it can be seen as technical construct, really is the first step in relaxing the notion of global observer equivalence. So I can help contemplating what completing this step implies - in particualr for string theory? Does most want to keep it a technical constcut, and not look that way?

The idea is: you can't have quantum De Sitter as a stable vacuum, and probably not even as a metastable vacuum, but maybe you can have it as an excited state on top of a stable Minkowski or Anti De Sitter vacuum.

Or maybe you can have it in some more general way, even removing the AdS or minkowski background? maybe to replace it with something else..? But then how are then the string themselves defined? Does it mean the strings themselves are emergent in some sense? Ie how to conceptaully define the equivalent of a "string" with its possible states of motion, without a fixed backrdoung? specifying the string itself seems probably intertwined with specicying the background. You probably cant separate them?

Any string researchers dare lookin this way?

/Fredrik

 

[Demystifier]

If you can't explain it simply, you don't understand it well enough.
- A. Einstein

 

[mad mathematician]

If you can't explain it simply, you don't understand it well enough.
- A. Einstein

Simple, not simpler...

If it's simple, then it must be simpler than something else, doesn't it?! :-D

 

[Fra]

Einstein also said

"Everything should be made as simple as possible, but not simpler"

Exactly how simple can somethig complex get? But 500 pages seems like a stretch.

/Fredrik