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• CommentRowNumber1.
• CommentAuthorUrs
• CommentTimeOct 26th 2009

I am starting landscape of string theory vacua -- hah! :-)

• CommentRowNumber2.
• CommentAuthorUrs
• CommentTimeJul 22nd 2011
• (edited Jul 22nd 2011)

I have added a recent reference by Mike Douglas, which stands out as at least clearly acknowledging the problem to be addressed

• CommentRowNumber3.
• CommentAuthorUrs
• CommentTimeAug 28th 2013

I took some time to collect and briefly comment on the central references, now listed here.

• CommentRowNumber4.
• CommentAuthorUrs
• CommentTimeJun 25th 2018
• (edited Jun 25th 2018)

added pointer to today’s Obied-Ooguri-Spodyneiko-Vafa 18.

Curious situation: After it had influenced much the development of the string theory community’s attention and almost all of its public media perception since 2003, after what must be thousands of followup publications, the argument of KKLT 03 for a large finite number of metastable de Sitter spacetime vacua of type IIB string theory is in the process of being abandoned for being plainly mathematically wrong.

Apparently the decisive blow was the focused and comprehensive analysis in Danielsson-VanRiet 18 of all the available arguments, which concluded that all this work is based on a mathematical assumption that was never checked and for which there is mounting evidence that it is just false.

If at the next social gathering smalltalk with your colleagues you need a good argument that physics does need mathematically rigorous proof after all, you’ll have a monumental example here.

What a waste of energy and time and of media attention! On the other hand, good to see that scientific scepticism is coming back, even if with 15 years of delay.

• CommentRowNumber5.
• CommentAuthorDavid_Corfield
• CommentTimeJun 25th 2018

Interesting!

In Danielsson-VanRiet 18, they write

Vasiliev gravity is thought to be the zero-tension limit of string theory, the opposite to the supergravity limit.

This is some form of higher spin gauge theory?

• CommentRowNumber6.
• CommentAuthorUrs
• CommentTimeJun 25th 2018
• (edited Jun 25th 2018)

Vasiliev gravity is thought to be the zero-tension limit of string theory, the opposite to the supergravity limit.

This is some form of higher spin gauge theory?

Yes, exactly. All this higher spin stuff supposedly is “just” string field theory in the limit of vanishing string tension.

This was “well known” since ancient times (I should try to collect reference) which is why I found it ironic and frustrating that in the last years parts of the community made a big deal of the “huge symmetry” found in higher spin theory, thereby ignoring that there is already a “huge and higher” symmetry in string field theory, in the guise of the (super) $L_\infty$-algebras. (That’s where the concept of $L_\infty$-algebra was first identified!)

• CommentRowNumber7.
• CommentAuthorUrs
• CommentTimeJun 27th 2018
• (edited Jun 27th 2018)

added pointer to followups by Vafa, that became available today: the followup preprint Agrawal-Obied-Steinhardt-Vafa 18 and the slides and recording of Vafa’s talk at Strings18 from two days back: Vafa 18.

So the trust in the 15 year old arguments is now shattered. One might hope that makes people beware to base the next argument on more solid analysis. Unfortunately, the above reference do not support that hope.

• CommentRowNumber8.
• CommentAuthorUrs
• CommentTimeAug 29th 2018
• (edited Aug 29th 2018)

That debate over existence of stringy de Sitter is getting big. Looks like I keep logging the exchange on PF here. A pleasure to watch Thomas Van Riet in action (see also here)

• CommentRowNumber9.
• CommentAuthorUrs
• CommentTimeDec 14th 2018

Added two new subsections to the References, one on scans of the landscape of type II vacua, the other on scans of the landscape of heterotic vacua

• CommentRowNumber10.
• CommentAuthorUrs
• CommentTimeMar 19th 2019

finally gave the Swampland its own References-subsection, here

• CommentRowNumber11.
• CommentAuthorUrs
• CommentTimeOct 29th 2019