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

In this letter a generic counterexample to the strong cosmic censorconjecture is exhibited. More precisely---taking into account that theconjecture lacks any precise formulation yet---first we make sense of what onewould mean by a "generic counterexample" by introducing the mathematicallyunambigous and logically stronger concept of a "robust counterexample". Thenmaking use of Penrose' nonlinear graviton construction (i.e., twistor theory)and a Wick rotation trick we construct a smooth Ricci-flat but not flatLorentzian metric on the largest member of the Gompf--Taubes uncountable radialfamily of large exotic ${\mathbb R}^4$'s. We observe that this solution of theLorentzian vacuum Einstein's equations with vanishing cosmological constantprovides us with a sort of counterexample which is weaker than a "robustcounterexample" but still reasonable to consider as a "generic counterexample".It is interesting that this kind of counterexample exists only in fourdimensions.

Exotica or the failure of the strong cosmic censorship in four dimensions