Hypersurface-deformation algebroids and effective spacetime models

Martin Bojowald, Umut Büyükçam, Suddhasattwa Brahma, Fabio D'Ambrosio

Research output: Contribution to journalArticle

24 Scopus citations

Abstract

In canonical gravity, covariance is implemented by brackets of hypersurface-deformation generators forming a Lie algebroid. Lie-algebroid morphisms, therefore, allow one to relate different versions of the brackets that correspond to the same spacetime structure. An application to examples of modified brackets found mainly in models of loop quantum gravity can, in some cases, map the spacetime structure back to the classical Riemannian form after a field redefinition. For one type of quantum corrections (holonomies), signature change appears to be a generic feature of effective spacetime, and it is shown here to be a new quantum spacetime phenomenon which cannot be mapped to an equivalent classical structure. In low-curvature regimes, our constructions not only prove the existence of classical spacetime structures assumed elsewhere in models of loop quantum cosmology, they also show the existence of additional quantum corrections that have not always been included.

Original languageEnglish (US)
Article number104032
JournalPhysical Review D
Volume94
Issue number10
DOIs
StatePublished - Jan 1 2016

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

Fingerprint Dive into the research topics of 'Hypersurface-deformation algebroids and effective spacetime models'. Together they form a unique fingerprint.

  • Cite this