Quotients of AdS_{p+1} x S^q: causally well-behaved spaces and black holes

TL;DR

This paper classifies quotients of AdS_{p+1} x S^q spaces, identifying which have well-behaved causal structures and interpreting certain quotients with closed timelike curves as black holes.

Contribution

It provides a detailed analysis of the causal properties of quotients of AdS x S spaces, linking them to black hole solutions and extending previous classifications.

Findings

Identified causally well-behaved quotients of AdS x S spaces.

Determined which quotients with closed timelike curves can be interpreted as black holes.

Connected quotient spaces to known solutions like Godel universes and black holes.

Abstract

Starting from the recent classification of quotients of Freund--Rubin backgrounds in string theory of the type AdS_{p+1} x S^q by one-parameter subgroups of isometries, we investigate the physical interpretation of the associated quotients by discrete cyclic subgroups. We establish which quotients have well-behaved causal structures, and of those containing closed timelike curves, which have interpretations as black holes. We explain the relation to previous investigations of quotients of asymptotically flat spacetimes and plane waves, of black holes in AdS and of Godel-type universes.