Background independence in a nutshell

Carlo Rovelli (1, 2) , Daniele Colosi (1, 2) , Luisa Doplicher (1, 2) , Winston Fairbairn (1, 2) , Leonardo Modesto (1, 2) , Karim Noui (3)

1 CPT - Centre de Physique Théorique - UMR 6207
2 CPT - Centre de Physique Théorique - UMR 7332
3 CGPG - Center for Gravitational Physics and Geometry

We study how physical information can be extracted from a background independent quantum system. We use an extremely simple `minimalist' system that models a finite region of 3d euclidean quantum spacetime with a single equilateral tetrahedron. We show that the physical information can be expressed as a boundary amplitude. We illustrate how the notions of ``evolution" in a boundary proper-time and ``vacuum" can be extracted from the background independent dynamics.

Mots clés: background independence; quantum gravity; problem of time

Domaines: Relativité Générale et Cosmologie Quantique [gr-qc]

Carlo Rovelli, Daniele Colosi, Luisa Doplicher, Winston Fairbairn, Leonardo Modesto, et al.. Background independence in a nutshell. Classical and Quantum Gravity, 2005, 22, pp.2971-2990. ⟨hal-00002673⟩