English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study cosmological properties of type IIA compactifications onorientifolds of SU(3)-structure manifolds with non-vanishing geometric flux.These compactifications give rise to effective 4D N=1 supergravity theoriesthat do not fall under some recently-proven no-go theorems against de Sittervacua and slow-roll inflation. Focusing on a well-understood class of modelsbased on coset spaces, however, we can use a refined no-go theorem that rulesout de Sitter vacua and slow-roll inflation in all but one case. The refinedno-go theorem uses the dilaton and a specific linear combination of the Kaehlermoduli, which is different from the overall volume modulus. It puts a lowerbound on the first slow-roll parameter: epsilon>=2. The only case not ruled outis the manifold SU(2)x SU(2), for which we indeed find critical points withepsilon numerically zero. However, all the points we could find have a tachyoncorresponding to an eta-parameter eta<= -2.4.

On the Cosmology of Type IIA Compactifications on SU(3)-structure Manifolds