Loop quantum cosmology and spin foams

Abhay Ashtekar, Miguel Campiglia, Adam Henderson

Research output: Contribution to journalArticlepeer-review

69 Scopus citations


Loop quantum cosmology (LQC) is used to provide concrete evidence in support of the general paradigm underlying spin foam models (SFMs). Specifically, it is shown that: (i) the physical inner product in the timeless framework equals the transition amplitude in the deparameterized theory; (ii) this quantity admits a vertex expansion a la SFMs in which the M-th term refers just to M volume transitions, without any reference to the time at which the transition takes place; (iii) the exact physical inner product is obtained by summing over just the discrete geometries; no 'continuum limit' is involved; and, (iv) the vertex expansion can be interpreted as a perturbative expansion in the spirit of group field theory. This sum over histories reformulation of LQC also addresses certain other issues which are briefly summarized.

Original languageEnglish (US)
Pages (from-to)347-352
Number of pages6
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Issue number4
StatePublished - Nov 9 2009

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics


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