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

The proposed dS/CFT correspondence remains an intriguing paradigm in thecontext of string theory. Recently it has motivated two interestingconjectures: the entropic N-bound and the maximal mass conjecture. The formerstates that there is an upper bound to the entropy in asymptotically de Sitterspacetimes, given by the entropy of pure de Sitter space. The latter statesthat any asymptotically de Sitter spacetime cannot have a mass larger than thepure de Sitter case without inducing a cosmological singularity. Here we reviewthe status of these conjectures and demonstrate their limitation. We firstdescribe a generalization of gravitational thermodynamics to asymptotically deSitter spacetimes, and show how to compute conserved quantities andgravitational entropy using this formalism. From this we proceed to adiscussion of the N-bound and maximal mass conjectures. We then illustrate thatthese conjectures are not satisfied for certain asymptotically de Sitterspacetimes with NUT charge. We close with a presentation of explicit examplesin various spacetime dimensionalities.Comment: 49 pages, 17 figures, a few typos corrected, addendum added with  regard to some references that were later brought to our attentio

A REVIEW OF THE N-BOUND AND THE MAXIMAL MASS CONJECTURES USING NUT-CHARGED dS SPACE–TIMES