# Negative cosmological constant from string theory

• A
• Demystifier

#### Demystifier

Gold Member
Allegedly, string theory (in it's simplest form) predicts that cosmological constant must be negative (or zero). Can someone explain where does this result come from? A reference would also be welcome.

Last edited:
There is no such "result".

There is no such "result".
Not even in older literature? Then how to interpret the statement by Witten
"In fact, classical or not, I don’t know any clear-cut way to get de Sitter space from string theory or M-theory. This last statement is not very surprising given the classical no go theorem. For, in view of the usual problems in stabilizing moduli, it is hard to get de Sitter space in a reliable fashion at the quantum level given that it does not arise classically."
in http://lanl.arxiv.org/abs/hep-th/0106109 ?

Last edited:
ohwilleke
String theory in AdS is a modern topic.

I'm not up to date to all the stringy constructions of backgrounds, but I think the problem you're addressing is deeper: it has to do with supersymmetry. E.g., pure N=1 D=4 supergravity can be constructed in a anti-deSitter background, but not a deSitter background. The reason is that the Jacobi identities of the underlying algebra don't allow for one particular sign of the cosmological constant (corresponding to dS).

Demystifier
I'm not up to date to all the stringy constructions of backgrounds, but I think the problem you're addressing is deeper: it has to do with supersymmetry. E.g., pure N=1 D=4 supergravity can be constructed in a anti-deSitter background, but not a deSitter background. The reason is that the Jacobi identities of the underlying algebra don't allow for one particular sign of the cosmological constant (corresponding to dS).
Thanks! Can you give a reference for that?

Hey, you changed the question from "must be negative" to "must be negative (or zero)". For the record, my answer pertained to the original version.

Demystifier
And you edited comment #3 to add the quote by Witten.

Demystifier
Thanks! Can you give a reference for that?
See e.g. Freedman& Van Proeyen their sugra textbook, page 251 onward. My supervisor Eric Bergshoeff also published on construction of deSitter sugra on the arxiv, e.g.

https://arxiv.org/abs/1507.08264