Duality and the Signature of Space-Time

TL;DR

This paper explores various spacetime signatures in M-theory and string theories, revealing how dualities connect different dimensional and signature configurations, suggesting they are limits of a single underlying framework.

Contribution

It uncovers the relationships between multiple spacetime signatures in M-theory and string theories through dualities, expanding the understanding of their interconnectedness.

Findings

Multiple spacetime signatures in M-theory and string theories identified.

Duality transformations connect theories with different numbers of time and space dimensions.

Field theory limits correspond to supergravities in various signatures.

Abstract

Versions of M-theory are found in spacetime signatures (9,2) and (6,5), in addition to the usual M-theory in 10+1 dimensions, and these give rise to type IIA string theories in 10-dimensional spacetime signatures (10,0),(9,1),(8,2),(6,4) and (5,5), and to type IIB string theories in signatures (9,1),(7,3) and (5,5). The field theory limits are 10 and 11 dimensional supergravities in these signatures. These theories are all linked by duality transformations which can change the number of time dimensions as well as the number of space dimensions, so that each should be a different limit of the same underlying theory.