Emergent Spacetime

TL;DR

The paper discusses the idea that space and time are emergent phenomena arising from more fundamental theories, reviewing related concepts, examples, and open questions in the field.

Contribution

It provides a comprehensive overview of the arguments and examples supporting the emergent nature of spacetime, highlighting current challenges and future prospects.

Findings

Space and time are likely emergent rather than fundamental.

Dualities introduce ambiguities in spatial geometry and topology.

Emergent space examples reveal complex underlying structures.

Abstract

We summarize the arguments that space and time are likely to be emergent notions; i.e. they are not present in the fundamental formulation of the theory, but appear as approximate macroscopic concepts. Along the way we briefly review certain topics. These include ambiguities in the geometry and the topology of space which arise from dualities, questions associated with locality, various known examples of emergent space, and the puzzles and the prospects of emergent time.