Kudos to Kea---category-QG acknowledgment http://arxiv.org/abs/gr-qc/0602120 Louis Crane (of Barrett-Crane spinfoam model) has a new paper about abstract categories approach ot QG---kind of thing Kea likes. check out the acknowledgments section Congratulations and cheers Kea Here's the arxiv posting Categorical Geometry and the Mathematical Foundations of Quantum General Relativity Louis Crane Contribution to the Oxford University Press volume on Quantum Gravity "We explore the possibility of replacing point set topology by higher category theory and topos theory as the foundation for quantum general relativity. We discuss the [Barrett-Crane] model and problems of its interpretation, and connect with the construction of causal sites." my comment: this is the first I have heard of an Oxford University Press volume on Quantum Gravity we know about a book edited by Daniel Oriti in the works at Cambridge U. P. (title variously reported as "Approaches to Quantum Gravity, towards a new understanding of spacetime") and I suppose Oriti's book would be a good place for this essay by Crane. But Crane says Oxford U.P. so unless he is mixing up the presses, there is another volume in the works.