Maybe it would give an idea of the currently active topics and who some of the active people are if we list the top 25 Loop papers of 2011 citewise:
HEP 203 records found 1 - 25
1.
Diffeomorphisms in group field theories.
Aristide Baratin (Ecole Polytechnique, CPHT & Saclay, SPhT & Orsay, LPT), Florian Girelli (Sydney U.), Daniele Oriti (Potsdam, Max Planck Inst.). Jan 2011. 31 pp.
http://arxiv.org/abs/1101.0590 [hep-th]
Cited by 40 records
2.
Zakopane lectures on loop gravity.
Carlo Rovelli (Marseille, CPT). Feb 2011. 25 pp.
http://arxiv.org/abs/1102.3660 [gr-qc]
Cited by 29 records
3.
Bubble divergences: sorting out topology from cell structure.
Valentin Bonzom, Matteo Smerlak. Mar 2011. 19 pp.
http://arxiv.org/abs/1103.3961 [gr-qc]
Cited by 18 records
4.
Loop Quantum Cosmology: A Status Report.
Abhay Ashtekar (Penn State U.), Parampreet Singh (Louisiana State U.). Aug 2011. 136 pp.
http://arxiv.org/abs/1108.0893 [gr-qc]
Cited by 17 records
5.
Observational constraints on loop quantum cosmology.
Martin Bojowald (Penn State U.), Gianluca Calcagni (Potsdam, Max Planck Inst.), Shinji Tsujikawa (Tokyo U. of Sci.). Jan 2011. 4 pp.
http://arxiv.org/abs/1101.5391 [astro-ph.CO]
Cited by 17 records
6.
Perfect discretization of reparametrization invariant path integrals.
Benjamin Bahr (Cambridge U. & Potsdam, Max Planck Inst.), Bianca Dittrich, Sebastian Steinhaus (Potsdam, Max Planck Inst.). Jan 2011. 8 pp.
http://arxiv.org/abs/1101.4775 [gr-qc]
Cited by 16 records
7.
Spin foam models with finite groups.
Benjamin Bahr, Bianca Dittrich, James P. Ryan. Mar 2011. 47 pp.
http://arxiv.org/abs/1103.6264 [gr-qc]
Cited by 15 records
8.
Spinor Representation for Loop Quantum Gravity.
Etera R. Livine, Johannes Tambornino. May 2011. 1 pp.
http://arxiv.org/abs/1105.3385 [gr-qc]
Cited by 13 records
9.
Regge gravity from spinfoams.
Elena Magliaro, Claudio Perini. May 2011. 8 pp.
http://arxiv.org/abs/1105.0216 [gr-qc]
Cited by 13 records
10.
Status of Horava gravity: A personal perspective.
Matt Visser (Victoria U., Wellington). Mar 2011. 11 pp.
http://arxiv.org/abs/1103.5587 [hep-th]
Cited by 13 records
11.
Spin foam models and the Wheeler-DeWitt equation for the quantum 4-simplex.
Valentin Bonzom (Perimeter Inst. Theor. Phys.). Jan 2011. 16 pp.
http://arxiv.org/abs/1101.1615 [gr-qc]
Cited by 13 records
12.
The Matter Bounce Curvaton Scenario.
Yi-Fu Cai (Arizona State U. & Beijing, Inst. High Energy Phys.), Robert Brandenberger (Beijing, Inst. High Energy Phys. & McGill U.), Xinmin Zhang (Beijing, Inst. High Energy Phys. & TPCSF, Beijing). Jan 2011. 15 pp.
http://arxiv.org/abs/1101.0822 [hep-th]
Cited by 13 records
13.
The Hamiltonian constraint in 3d Riemannian loop quantum gravity.
Valentin Bonzom, Laurent Freidel (Perimeter Inst. Theor. Phys.). Jan 2011. 24 pp.
http://arxiv.org/abs/1101.3524 [gr-qc]
Cited by 12 records
14.
Cosmological constant in spinfoam cosmology.
Eugenio Bianchi (Marseille, CPT), Thomas Krajewski (Marseille, CPT & Orsay, LPT), Carlo Rovelli (Marseille, CPT), Francesca Vidotto (Marseille, CPT & Pavia U. & INFN, Pavia). Jan 2011. 4 pp.
http://arxiv.org/abs/1101.4049 [gr-qc]
Cited by 11 records
15.
Coarse graining methods for spin net and spin foam models.
Bianca Dittrich, Frank C. Eckert, Mercedes Martin-Benito (Potsdam, Max Planck Inst.). Sep 2011. 39 pp.
http://arxiv.org/abs/1109.4927 [gr-qc]
Cited by 10 records
16.
Observational test of inflation in loop quantum cosmology.
Martin Bojowald (Penn State U.), Gianluca Calcagni (Potsdam, Max Planck Inst.), Shinji Tsujikawa (Tokyo U. of Sci.). Jul 2011. 37 pp.
http://arxiv.org/abs/1107.1540 [gr-qc]
Cited by 10 records
17.
Holomorphic Simplicity Constraints for 4d Spinfoam Models.
Maite Dupuis (Lyon, IPN & Sydney U.), Etera R. Livine (Lyon, IPN). Apr 2011. 27 pp.
http://arxiv.org/abs/1104.3683 [gr-qc]
Cited by 10 records
18.
Chern-Simons theory, Stokes' Theorem, and the Duflo map.
Hanno Sahlmann (APCTP, Pohang), Thomas Thiemann (Erlangen - Nuremberg U., Theorie III). Jan 2011. 26 pp.
http://arxiv.org/abs/1101.1690 [gr-qc]
Cited by 10 records
19.
Quantum simplicial geometry in the group field theory formalism: reconsidering the Barrett-Crane model.
Aristide Baratin, Daniele Oriti. Aug 2011. 24 pp.
http://arxiv.org/abs/1108.1178 [gr-qc]
Cited by 9 records
20.
Tensor models and hierarchy of n-ary algebras.
Naoki Sasakura (Kyoto U., Yukawa Inst., Kyoto). Apr 2011. 13 pp.
http://arxiv.org/abs/1104.5312 [hep-th]
Cited by 9 records
21.
Cosmological Constant in LQG Vertex Amplitude.
Muxin Han (Marseille, CPT). May 2011. 4 pp.
http://arxiv.org/abs/1105.2212 [gr-qc]
Cited by 8 records
22.
Euclidean three-point function in loop and perturbative gravity.
Carlo Rovelli, Mingyi Zhang (Marseille, CPT). May 2011. 16 pp.
http://arxiv.org/abs/1105.0566 [gr-qc]
Cited by 8 records
23.
Canonical quantization of non-commutative holonomies in 2+1 loop quantum gravity.
K. Noui (Tours U., CNRS), A. Perez, D. Pranzetti (Marseille, CPT). May 2011.
http://arxiv.org/abs/1105.0439 [gr-qc]
Cited by 8 records
24.
Tensor models and 3-ary algebras.
Naoki Sasakura (Kyoto U., Yukawa Inst., Kyoto). Apr 2011. 18 pp.
http://arxiv.org/abs/1104.1463 [hep-th]
Cited by 8 records
25.
Curvature in spinfoams.
Elena Magliaro, Claudio Perini (Penn State U.). Mar 2011. 6 pp.
http://arxiv.org/abs/1103.4602 [gr-qc]
Cited by 8 records