Ashtekar's "Shadow states" paper There is this paper by Ashtekar, Fairhurst, and Willis called "Quantum gravity, shadow states, and quantum mechanics" http://arxiv.org/gr-qc/0207106 Citebase lists it as having been cited 5 times, one of which was in a paper by one of the authors. The other 4 citations were: 1.Alfaro, J ; Morales-Tecotl, H A ; Urrutia, L F "Quantum gravity and spin 1/2 particles effective dynamics" Abstract:"Quantum gravity phenomenology opens up the possibility of probing Planck scale physics...." 2.Lusanna, Luca; Pauri, Massimo "General Covariance and the Objectivity of Space-Time Point-Events: The Physical Role of Gravitational and Gauge Degrees of Freedom in General Relativity" Abstract: "...The work is carried through in metric gravity for the class of Christoudoulou-Klainermann space-times, in which the ..." 3.Pullin, Jorge "Canonical quantization of general relativity: the last 18 years in a nutshell" Abstract: "This is a summary of the lectures presented at the Xth Brazilian school on cosmology and gravitation. The style of the text is that of a lightly written descriptive summary of ideas with almost no formulas, with pointers to the literature. We hope this style can encourage new people to take a look ..." 4.Corichi, Alejandro; Cortez, Jeronimo; Quevedo, Hernando "Note on Canonical Quantization and Unitary Equivalence in Field Theory" The problem of defining and constructing representations of the Canonical Commutation Relations can be systematically approached via the technique of algebraic quantization. In particular, when the phase space of the system is linear and finite dimensional..." -------------- I could not see from this how the paper fitted into the current mainstream development of LQG. There seemed to be no research line issuing from it, as if it represented a gambit that proved to be a blind alley. Since I wanted to find if and how the paper relates to the main body of LQG, I looked for references in Rovelli's "Quantum Gravity". Rovelli's citations are not in Citebase so there was some expectation of finding the paper. In fact Rovelli's book has 385 citations including many by Ashtekar (more than I felt like counting) but no reference is made to this "Shadow state" paper. What is wrong? Is this particular paper unrelated to LQG proper? So I looked at another large bibliography, and found plenty of Ashtekar but no mention of this paper, so I lost hope. Maybe someone else will turn up a citation indicating how this "Shadow state" paper connects to the main Loop Gravity picture.