Robustness of key features of loop quantum cosmology

Abhay Ashtekar, Alejandro Corichi, Parampreet Singh

Research output: Contribution to journalArticlepeer-review

350 Scopus citations


A small simplification based on well-motivated approximations is shown to make loop quantum cosmology of the k=0 Friedman-Robertson-Walker model (with a massless scalar field) exactly soluble. Analytical methods are then used i) to show that the quantum bounce is generic; ii) to establish that the matter density has an absolute upper bound which, furthermore, equals the critical density that first emerged in numerical simulations and effective equations; iii) to bring out the precise sense in which the Wheeler-DeWitt theory approximates loop quantum cosmology and the sense in which this approximation fails; and iv) to show that discreteness underlying loop quantum cosmology is fundamental. Finally, the model is compared to analogous discussions in the literature and it is pointed out that some of their expectations do not survive a more careful examination. An effort has been made to make the underlying structure transparent also to those who are not familiar with details of loop quantum gravity.

Original languageEnglish (US)
Article number024046
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number2
StatePublished - Jan 29 2008

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


Dive into the research topics of 'Robustness of key features of loop quantum cosmology'. Together they form a unique fingerprint.

Cite this