COVID19 information for PI Residents and Visitors
Support for this conference is provided by The Templeton Frontiers Program.
Quantum gravity aims at unifying Einstein's vision of spacetime as a dynamical object with the realization that fundamental physics and hence spacetime has to be quantum. This opens up a large variety of research questions and directions, which range from foundational physical issues having to do with the nature of space and time, to current searches for experimental signatures of quantum spacetime.
This conference, which is part of the series of Loops conferences, will present and review recent progress and highlights in loop quantum gravity and other quantum gravity approaches. We will focus mainly on background independent approaches which are approaches that do not depend on perturbation theory formulated in a classical background.
Plenary talks will highlight the most important recent developments in quantum gravity research. Afternoon (parallel) sessions are open to contributed talks and will be focussed on particular topics or subfields and give room for discussions, exchange of ideas and a critical assessment of open questions.
The conference will bring quantum gravity researchers from all over the world together and we also hope to share the excitement of quantum gravity research with participants from other research fields.
Previous conferences in this series were:
 2004: Marseille: Non Perturbative Quantum Gravity: Loops and Spin Foams, 37 May 2004
 2005: AEIGolm: Loops '05, 1014 October 2005
 2007: Morelia: LOOPS '07, 25  30 June 2007
 2008: Nottingham: Quantum Gravity and Quantum Geometry, June 30th  July 4th 2008.
 2009: Beijing: Loops ’09, 27 August 2009
 2011: Madrid: Loops 11, 23  28 May 2011
Registration for this confernce is now closed.
Sponsorship for this conference has been provided by:
 Ivan Agullo, DAMTP Cambridge
 Abhay Ashtekar, Pennsylvania State University
 Aurelien Barrau, Universite Joseph Fourier
 Eugenio Bianchi, Perimeter Institute
 Steve Carlip, University of California, Davis
 Fay Dowker, Imperial College, London
 Henrique de Andrade Gomes, University of California, Davis
 Dafne Guetta, ORTBraude College & INAFOAR
 Razvan Gurau, Université ParisSud
 Muxin Han, Centre de Physique Theorique
 Frank Hellmann, Max Planck Institute for Gravitational Physics
 Viqar Husain, University of New Brunswick
 Kirill Krasnov, University of Nottingham
 Etera Livine, Ens de Lyon
 Renate Loll, Radboud University Nijmegen
 Alejandro Perez, Centre de Physique Theorique
 Vincent Rivasseau, Universite ParisSud XI Orsay
 Carlo Rovelli, Le Centre de Physique Théorique
 Frank Saueressig, Radboud University Nijmegen
 David Skinner, DAMTP Cambridge, Institute for Advanced Study
 Bill Unruh, University of British Columbia
 Madhavan Varadarajan, Raman Research Institute
 Niayesh Afshordi, Perimeter Institute
 Emanuele Alesci, University of Warsaw
 Giovanni AmelinoCamelia, La Sapienza University of Rome
 Mohamed Anber, University of Toronto
 Fabio Anza, Universit di Pisa
 Seramika Ari Wahyoedi, Centre de Physique Theorique
 Mehdi Assanioussi, University of Warsaw
 Valerio Astuti, La Sapienza University of Rome
 Angel Ballesteros, Universidad de Burgos
 Andrzej Banburski, Perimeter Institute
 Aristide Baratin, Albert Einstein Institute
 Julian Barbour, University of Oxford
 Leonardo Barcaroli, La Sapienza University of Rome
 Jacob Barnett, Perimeter Institute
 Dario Benedetti, Albert Einstein Institute
 Joseph Bengeloun, Perimeter Institute
 Paolo Bertozzini, Thammasat University
 Stefano Bianco, La Sapienza University of Rome
 Norbert Bodendorfer, Pennsylvania State University
 Martin Bojowald, Pennsylvania State University
 Boris Bolliet, ENS de Lyon
 Julien Bolmont, LPNHE & UPMC
 Valentin Bonzom, Perimeter Institute
 Suddhsattwa Brahma, Pennsylvania State University
 Will Bunting, California Institute of Technology
 Thomas Cailleteau, Pennsylvania State University
 Jose Ricardo Cames de Oliveira, University of Nottingham
 Miguel Campiglia, Raman Research Institute
 Sylvain Carrozza, Albert Einstein Institute
 Mariano Celada, CINVESTAV
 Atousa Chaharsough Shirazi, Florida Atlantic University
 LinQing Chen, Perimeter Institute
 Goffredo Chirco, AixMarseille University
 Christopher ColemanSmith, Duke University
 Francois Collet, AixMarseille University
 Frederic Combes, Perimeter Institute
 Rory Conboye, University College Cork
 Adriano Contillo, Radboud University Nijmegen
 Joshua Cooperman, University of California, Davis
 Leonard Cottrell, Retired
 Antonin Coutant, Albert Einstein Institute
 Andrea Dapor, University of Warsaw
 Stephane Dartois, ENS de Lyon
 Ghanashyam Date, The Institute of Mathematical Sciences
 Bogar Diaz Jimenez, Benemrita Univesidad Autnoma de Puebla
 Jacobo Diaz Polo, Louisiana State University
 Bianca Dittrich, Perimeter Institute
 Andreas Doering, University of Oxford
 Pietro Dona, SISSA
 Maite Dupuis, University of ErlangenNuernberg
 Christopher Duston, Florida State University
 Astrid Eichhorn, Perimeter Institute
 Jonathan Engle, Florida Atlantic University
 Kevin Falls, University of Sussex
 Laurent Freidel, Perimeter Institute
 Ivette Fuentes, University of Nottingham
 Rodolfo Gambini, Universidad de la Republica
 Marc Geiller, Institute for Gravitation and the Cosmos
 Adam Getchell, University of California, Davis
 Steffen Gielen, Perimeter Institute
 Florian Girelli, University of Waterloo
 Lisa Glaser, Niels Bohr Institute
 Julien Grain, Institute for Space Astrophysics
 Jonathan Granot, Open University of Israel
 Sean Gryb, Radboud University Nijmegen
 Giulia Gubitosi, La Sapienza University of Rome
 Hal Haggard, Centre de Physique Theorique
 Maximilian Hanusch, University of Paderborn
 Bruno Hartmann, Perimeter Institute
 Asif Hassan, University of Texas, Austin
 Jeffrey Hazboun, Utah State University
 Tobias Henz, University of Heidelberg
 Gabe Herczeg, University of California, Davis
 Hector Hernandez, Universidad Autonoma de Chihuahua
 Daniel Fernando Higuita Borja, CINVESTAV
 Jeff Hnybida, Perimeter Institute
 Philipp Hoehn, Perimeter Institute
 Matthew Hogan, Florida Atlantic University
 Giorgio Immirzi, INFN
 Matt Johnson, Perimeter Institute
 Oleg Kabernik, University of Waterloo
 Mikhail Kagan, Pennsylvania State University
 Wojciech Kaminski, Perimeter Institute
 Nima Khosravi, African Institute for Mathematical Sciences
 Marcin Kisielowski, University of Warsaw
 Tim Koslowski, University of New Brunswick
 Thomas Krajewski, Centre de Physique Theorique
 Manuel Kramer, University of Cologne
 Emilia Kubalova, Masaryk University
 Eugene Kur, University of California, Berkeley
 Suzanne Lanery, University of ErlangenNuernberg
 Antony Lee, University of Nottingham
 Jerzy Lewandowski, University of Warsaw
 Linda Linsefors, LPSCGrenoble & CNRS
 Kinjalk Lochan, Tata Institute Of Fundamental Research
 Niccol Loret, La Sapienza University of Rome
 Matteo Giuseppe Lostaglio, Imperial College, London
 Yongge Ma, Beijing Normal University
 Anson Maitland, University of Waterloo
 Seth Major, Hamilton College
 Antonio Marciano, Fudan University & INFN
 Mercedes Martin Benito, Perimeter Institute
 Eduardo MartinMartinez, Perimeter Institute & Institute for Quantum Computing
 Daniel Martin de Blas, Instituto de Estructura de la Materia
 Marco Matassa, SISSA
 Guillermo Mena, Instituto de Estructura de la Materia
 Phillip Mendonca, Florida Atlantic University
 Flavio Mercati, Perimeter Institute
 Aleksander Mikovic, Lusofona University
 Jonah Miller, University of Colorado
 Djordje Minic, Virginia Tech
 Edison Montoya, Instituto de Fisica y Matematicas
 Tim Morris, University of Southampton
 Markus Mueller, Perimeter Institute
 Yasha Neiman, Pennsylvania State University
 Robert Oeckl, Centro de Ciencias Matematicas
 Javier Olmedo, Universidad de la Repblica de Uruguay
 Jonathan Oppenheim, University College London
 Daniele Oriti, Albert Einstein Institute
 Prince Osei, African Institute for Mathematical Sciences
 Dine Ousmane Samary, International Chair in Mathematical Physics and Applications
 Giovanni Palmisano, La Sapienza University of Rome
 Sohyun Park, Institute for Gravitation and the Cosmos
 Daniele Pranzetti, Albert Einstein Institute
 Isabeau PremontSchwarz, Albert Einstein Institute
 Jacek Puchta, University of Warsaw
 Jorge Pullin, Louisiana State University
 Jason Pye, University of Waterloo
 Matti Raasakka, University ParisNord XIII
 Saeed Rastgoo, Centro de Ciencias Matematicas
 Michael Reisenberger, Instituto de Física Facultad de Ciencias
 Trevor Rempel, Perimeter Institute
 Juan D Reyes, Universidad Autonoma Metropolitana
 Aldo Riello, AixMarseille University
 Andreas Rodigast, Heidelberg University
 Irais Rubalcava Garcia, Centro de Ciencias Matematicas
 James Ryan, Albert Einstein Institute
 David Schroeren, Balliol College
 Bernd Schroers, HeriotWatt University
 Sanjeev Seahra, University of New Brunswick
 Giuseppe Sellaroli, University of Waterloo
 Vasudev Shyam, The Center For Fundamental Research and Creative Education
 Lorenzo Sindoni, Albert Einstein Institute
 Matteo Smerlak, Albert Einstein Institute
 Lee Smolin, Perimeter Institute
 Rafael Sorkin, Perimeter Institute
 Robert Spekkens, Perimeter Institute
 Simone Speziale, Centre de Physique Theorique
 Sebastian Steinhaus, Perimeter Institute
 Alexander Stottmeister, University of ErlangenNuernberg
 Eckhard Strobel, La Sapienza University of Rome
 Sumati Surya, Raman Research Institute
 Jdrzej Swiezewski, University of Warsaw
 Sara Tavares, University of Nottingham
 Karim Thebault, LMU Munich
 Johannes Thurigen, Albert Einstein Institute
 Casey Tomlin, Pennsylvania State University
 Aaron Trout, Chatham University
 Artur Tsobanjan, American University
 Mercedes Velazquez, CINVESTAV
 Madhavan Venkatesh, Centre for Fundamental Research and Creative Education
 Francesca Vidotto, Radboud University Nijmegen
 Hans Westman, Instituto de Fisica Fundamental
 Wolfgang Martin Wieland, AixMarseille University
 Edward WilsonEwing, Louisiana State University
 Felix Winterhalter, University of ErlangenNuernberg
 Andreas J. Woehr, Eberhard Karls University
 Yuki Yokokura, Kyoto University
 Mingyi Zhang, Centre de Physique Theorique
 Thomas Zilker, University of ErlangenNuernberg
 Antonia Zipfel, University of ErlangenNuernberg
 Jonathan Ziprick, Perimeter Institute
Parallel Session Breakdown.pdf
Time 
Event 
Location 
8:309:00am 
Registration 
Reception 
9:009:10am 
Lee Smolin & Neil Turok 
Theater 
9:109:55am 
Ivan Agullo, DAMTP Cambridge 
Theater 
9:5510:40am 
Aurelien Barrau, Universite Joseph Fourier 
Theater 
10:4011:00am 
Coffee Break 
Bistro 
11:0011:45am 
Dafne Guetta, ORTBraude College & INAFOAR 
Theater 
11:4512:30pm 
Henrique de Andrade Gomes, University of California, Davis 
Theater 
12:302:30pm 
Lunch 
Bistro 
2:304:10pm 
Parallel Discussion Groups 

2:304:10pm 
Quantum Cosmology 
Theater 
2:304:10pm 
Shape Dynamics 
Time Room 
2:304:10pm 
Spin Foams 
PSI Workroom 
2:304:10pm 
Black Holes 
Space Room 
4:104:40pm 
Coffee Break 
Bistro 
4:406:20pm 
Quantum Cosmology 
Theater 
4:406:00pm 
Shape Dynamics 
Time Room 
4:406:00pm 
Spin Foams 
PSI Workroom 
4:406:00pm 
Black Holes 
Space Room 
6:006:20pm  Conference Photo  TBA 
6:20pm 
Poster Session 
Atrium 
6:20pm 
Pub Night 
Bistro 
Time 
Event 
Location 
9:009:45am 
Alejandro Perez, Centre de Physique Theorique 
Theater 
9:4510:30am 
Eugenio Bianchi, Perimeter Institute 
Theater 
10:3011:00am 
Coffee Break 
Bistro 
11:0011:45am 
Bill Unruh, University of British Columbia 
Theater 
11:4512:30pm 
Frank Saueressig, Radboud University Nijmegen 
Theater 
12:3012:35pm  TorQ Percusion Quartet How can you make space and time quantum? 
Theater 
12:352:30pm 
Lunch 
Bistro 
2:304:10pm 
Renormalization 
Bob Room 
2:304:10pm 
Phenomenology 
Time Room 
2:304:10pm 
Canonical Quantum Gravity 
PSI Workroom 
2:304:10pm 
Black Holes 
Space Room 
4:104:40pm 
Coffee Break 
Bistro 
4:406:00pm 
Renormalization 
Bob Room 
4:406:00pm 
Phenomenology 
Time Room 
4:406:00pm 
Canonical Quantum Gravity 
PSI Workroom 
4:406:00pm 
Quantum Cosmology 
Space Room 
6:006:20pm 
Break 
Bistro 
Panel Discussions (Each panel discussion is scheduled for 70 minutes) 

6:207:30pm  Chair: Astrid Eichhorn What is the most important fact we have learnt about quantum gravity? B. Dittrich, F. Dowker, V. Husain, R. Loll, C. Rovelli, F. Saueressig 
Theater 
7:308:40pm  Chairs: Steffen Gielen & Mercedes Martin Benito What does quantum gravity teach us about the very early universe? G. Mena Marugan, D. Oriti, J. Grain 
Bob Room 
7:308:40pm  Chair: Eugenio Bianchi On the nature of black hole entropy L. Freidel, A. Perez, C. Rovelli, R. Sorkin, B. Unruh 
Theater 
Time 
Event 
Location 
9:009:45am 
Etera Livine, Ens de Lyon 
Theater 
9:4510:30 
David Skinner, DAMTP Cambridge & Institute for Advanced Study Twistor Strings for N=8 Supergravity 
Theater 
10:3011:00am 
Coffee Break 
Bistro 
11:0011:45am 
Vincent Rivasseau, Universite ParisSud XI Orsay 
Theater 
11:4512:30pm 
Razvan Gurau, Université ParisSud 
Theater 
12:301:15pm 
Muxin Han, Centre de Physique 
Theater 
1:152:30pm 
Lunch 
Bistro 
2:005:00pm 
Soccer 
Waterloo Park 
6:00pm 
Conference BBQ 
Bistro 
Time 
Event 
Location 
9:009:45am 
Frank Hellmann, Max Planck Institute for Gravitational Physics Asymptotic dynamics: Spin foam partition functions 
Theater 
9:4510:30am 
Fay Dowker, Imperial College, London 
Theater 
10:3010:35  Special Announcement  Theater 
10:3511:00am 
Coffee Break 
Bistro 
11:0011:45am 
Madhavan Varadarajan, Raman Research Institute 
Theater 
11:4512:30pm 
Renate Loll, Radboud University Nijmegen 
Theater 
12:302:30pm 
Lunch 
Bistro 
2:304:10pm 
Group Field Theory, Tensor Models 
Bob Room 
2:304:10pm 
Phenomenology 
Time Room 
2:304:10pm 
Canonical Quantum Gravity 
PSI Workroom 
2:304:10pm 
Discrete Approaches 
Space Room 
4:104:40pm 
Coffee Break 
Bistro 
4:406:00pm 
Group Field Theory, Tensor Models 
Bob Room 
4:406:00pm 
Phenomenology 
Time Room 
4:406:00pm 
Canonical Quantum Gravity 
PSI Workroom 
4:406:00pm 
Discrete Approaches 
Space Room 
6:006:40pm 
Break 
Bistro 
7:30pm9:30pm 
TorQ Percussion Concert 
Theater 
9:30pm 
Reception 
Bistro 
Time 
Event 
Location 
9:009:45am 
Steve Carlip, University of California, Davis 
Theater 
9:4510:30am 
Kirill Krasnov, University of Nottingham 
Theater 
10:3011:00am 
Coffee Break 
Bistro 
11:0011:45am 
Viqar Husain, University of New Brunswick 
Theater 
11:451:00pm 
Abhay Ashtekar, Pennsylvania State University 
Theater 
1:001:10pm  Acknowledgements to Participants  Theater 
1:102:30pm 
Lunch 
Bistro 
2:304:10pm 
Quantum Cosmology 
Bob Room 
2:304:10pm 
Quantum Foundations 
Time Room 
2:304:10pm 
Discrete Approaches / Mixed Session 
PSI Workroom 
2:304:10pm 
Canonical Quantum Gravity / Spin Foams 
Space Room 
4:104:40pm 
Coffee Break 
Bistro 
4:406:00pm 
Quantum Cosmology 
Bob Room 
4:406:00pm 
Quantum Foundations 
Time Room 
4:406:00pm 
Renormalization 
PSI Workroom 
4:406:00pm 
Mixed Session 
Space Room 
Parallel Session Abstracts.pdf
Plenary Speaker Abstracts:
Ivan Agullo, DAMTP Cambridge
A Quantum Gravity Extension of the Inflationary Scenario
Since the standard inflationary paradigm is based on quantum field theory on classical spacetimes, it excludes the Planck era. Using techniques from loop quantum gravity, the theory is extended to overcome this limitations. The new framework sharpens conceptual issues by distinguishing between the true and apparent transPlanckian difficulties and provides sufficient conditions under which the true difficulties can be overcome within a quantum gravity theory, with interesting lessons for both theory and observations.
Abhay Ashtekar, Pennsylvania State University
Promising Paths
In LQG we work in the spirit of Antonio Machado: "Traveler, there is no path; Paths are made by walking." I will present a bird's eye view of some of the paths that have emerged since Loops 11 and offer a few suggestions.
Aurelien Barrau, Universite Joseph Fourier
Some possible ways to observe consequences of loop quantum gravity
In this talk, I'll briefly review some possible observational consequences of loop quantum gravity. I will first address the issue of the closure of the algebra of constraints in holonomycorrected effective loop quantum cosmology for tensor, vector, and scalar modes. I will underline some unexpected features like a possible change of signature. The associated primordial power spectrum and the basics of the related CMB analysis will be presented. The "asymptotic silence" hypothesis will be mentioned as a promising alternative. Then, I'll address the issue of the probability for inflation and the prediction of its duration from a new perspective. Finally, I'll present some prospect about the evaporation of black holes in LQG.
Eugenio Bianchi, Perimeter Institute
Entanglement, BekensteinHawking Entropy, and Spinfoams
I review recent developments on vacuum entanglement perturbations in perturbative quantum gravity and spinfoams, and discuss their relevance for understanding the nature of black hole entropy.
Steve Carlip, University of California, Davis
Spontaneous Dimensional Reduction?
Several lines of evidence hint that quantum gravity at distances a bit larger than the Planck scale may become effectively twodimensional. I will summarize the evidence for this "spontaneous dimensional reduction," and suggest a further argument based on the effect of vacuum fluctuations on light cones. If this description proves to be correct, it suggests an interesting relationship between smallscale quantum spacetime and the behavior of cosmologies near a spacelike singularity.
Fay Dowker, Imperial College, London
Causal Sets and the Quantum of Action
The struggle between local and global concepts in physics comes to a head in causal set quantum gravity. Local physics  and general relativity in particular  must be recovered in a continuum approximation if the theory is to be successful but causal sets are inherently nonlocal entities. I will describe a family of causal set actions labelled by dimension, each of which is nonlocal and yet, when applied to certain causal sets, approximates the Einstein Hilbert action and is therefore effectively local. I will explain why this is a source of hope that causal set theory has a continuum approximation.
Henrique de Andrade Gomes, University of California, Davis
Shape Dynamics: a status report
I will give an introduction to the theory of Shape Dynamics, and then comment on recent advances, obstacles and future projects.
Dafne Guetta, ORTBraude College & INAFOAR
Quantum Gravity Phenomenology with Neutrinos and high energy photons.
I review the main properties of the Gamma Ray Bursts (GRBs) as possible sources of high energy (E>TeV) neutrinos and confirmed sources of high energy (E>GeV) photons.
I discuss the possibility to use the data of neutrino telescopes, such as IceCube and the GeVphoton telescopes, such as Fermi’s LAT, for precision tests of Einstein's Special Relativity as applied to neutrinos and photons. My focus is on possible departures from Special Relativity that can be motivated by models of quantum spacetime. I observe that neutrinos which one would not associate to a GRB, when assuming a classical spacetime picture, may well be GRB neutrinos if the possibility that Lorentz invariance is broken at very high energies is taken into account. I outline how future analyses of neutrino data should be done in order to systematically test the Lorentz Invariance Violation possibility. In addition I consider the possibility that Lorentz Invariance Violation might be responsible for the spectral lags that characterize the GeV signal observed for the remarkable GRB130427A.
A comparison of these features for GRBs at different redshifts provides some encouragement for a redshift dependence of the effects of the type expected for a quantumspacetime interpretation, but other aspects of the analysis appear to invite the interpretation as intrinsic properties of GRBs.
Razvan Gurau, Universite ParisSud
he non perturbative 1/N expansion of Tensor Models
I will present the recently obtained non perturbative 1/N expansion of tensor models. The correlation functions are shown to be analytic in the coupling constant in some domain of the complex plane and to support appropriate scaling bounds at large N. Surprisingly, the non perturbative setting turns out to be a powerful computational tool allowing the explicit evaluation order by order (with bounded rest terms) of the correlations.
Muxin Han, Centre de Physique Theorique
Spinfoam Formulation of Loop Quanum Gravity
Recently there are a lot of progresses in developing the spinfoam formulation of loop quantum gravity. In this talk I give an overview of the subject. I introduce the formalism and the motivation of the theory, and I discuss the application of spinfoam formulation in black hole and cosmology. I also discuss the inclusion of the quantum matter fields and cosmological constant in the formalism. The inclusion of cosmological constant motivates a ChernSimons formulation of LQG. Finally I discuss the semiclassical lowenergy approximation of the spinfoam formulation, where Einstein gravity appears as the leading contribution.
Frank Hellmann, Max Planck Institute for Gravitational Physics
Asymptotic dynamics: Spin foam partition functions in the asymptotic regime
Spin foam models are models for space time built from discrete chunks of quantized geometry. In the asymptotic regime the classical geometry is regained.
Scenes from polymer quantization
A regime of "polymer quantum field theory on curved spacetime" should emerge in a low energy approximation of quantum gravity based on LQG ideas. This era should be characterized by a polymer scale, and give modifications to the usual semiclassical approximation. I will describe work on gravitational collapse, cosmology, and statistical mechanics in this setting. Results include models of horizon evaporation, inflation and graceful exit without an inflaton potential, and an indication of dimensional reduction from 4 to 2.5 dimensions.
Kirill Krasnov, University of Notthingham Diffeomorphism Invariant Gauge Theories
I will describe a very large class of gauge theories that do not use any external structure such as e.g. a spacetime metric in their construction. When the gauge group is taken to be SL(2) these theories describe interacting gravitons, with GR being just a particular member of a whole family of gravity theories. Taking larger gauge groups one obtains gravity coupled to various matter systems. In particular, I will show how gravity together with YangMills gauge fields arise from one and the same diffeomorphism invariant gauge theory Lagrangian. Finally, I will describe what is known about these theories quantum mechanically.
Etera Livine, Ens de Lyon
Spinor and Twistor networks in Loop Gravity
I will review the reformulation of the loop gravity phase space in terms of spinor networks and twistor networks, and present how these techniques can be used to write spinfoam amplitudes as discretized path integrals and to study the dynamics that they define (recursion, Hamiltonian constraints as differential equations).
Renate Loll, Radboud University Nijmegen
Causal Dynamical Triangulations without Preferred Foliation
We introduce a generalized version of the Causal Dynamical Triangulations (CDT) formulation of quantum gravity, in which the regularized, triangulated path integral histories maintain their causal properties, but do not have a preferred propertime foliation. An extensive numerical study of the associated nonperturbative path integral in 2+1 dimensions shows that it can nevertheless reproduce the emergence of an extended de Sitter universe on large scales, a key feature of CDT quantum gravity. This suggests that the preferred foliation normally used in CDT is not a crucial (although convenient) part of its background structure.
Alejandro Perez, Centre de Physique Theorique
Black holes in loop quantum gravity: new insights and perspectives from semiclassical consistency
A Shift in Time featuring the TorQ Percussion Quartet Thursday, July 25th @ 7:30pm Mike Lazaridis Theatre, Perimeter Institute Loops 13 features a unique concert opportunity that integrates art with science. This musical presentation reveals a special duality between quantum gravity and sound featuring the talents of the TorQ Percussion Quartet. TorQ’s program “A Shift in Time” examines the phenomenon of time and space in a rhythmic paradigm. Each piece explores a specific music compositional device and variations surrounding it, including metric modulation, phasing, spatial aural spectra, and acoustic delay. During the conference period the TorQ Percussion Quartet will engage with our delegates and PI community and these interactions will provide inspiration for improvisational pieces for the upcoming concert. Don't miss out on this fantastic event, an evening of percussion mastery presented by the TorQ Percussion Quartet, featuring sounds from the driving rhythms of wood to the Doppler pulsations of metallic keyboard instruments. Reserve your ticket now! For more information on TorQ visit: http://www.
All participants of the Loops 13 conference are encouraged to dine in Perimeter Institute’s Black Hole Bistro. The following events have been scheduled for your enjoyment.
Monday, July 22
A pub style buffet will be available serving the following items:
• Grilled Canadian Bacon, Lettuce & Tomato Sandwich on Toasted Onion Seed Soft Roll $6
• Fish Taco, Cornmeal Crusted Perch, Asian Slaw, Thai Chili Sauce $6
• Smoked Tempeh Bacon Poutine, Miso Gravy $5
• Grilled Ontario Corn and Potato salad $4
• Chocolate Fudge Brownie Bar $4
• Cash Bar
This opening night event will coincide with the poster session taking place in the Atrium
Wednesday, July 24 Conference BBQ.
Please come join your fellow conference participants in the bistro for dinner. There is no charge to attend this dinner.
Thursday, July 25
A reception will take place immediately following the TorQ Percussion Quartet concert. Concert attendees may enjoy a beverage and light snacks after the performance. There is no charge to attend the reception.
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Loops '13 Football Tournament a.k.a.the 2nd edition of the Loops' mini world cup tournament
After a first edition organized during the Madrid conference during Loops' 11, the Loops' Cup is back! While the 2011 tournament was won by an international selection, we are planning to change the format of the cup; it will be organzied most likely by research topics instead of national teams (since there were not enough nationals for each country last time). We are planning to play on Wednesday afternoon (July 24) in Waterloo Park. A field has been reserved for play from 2:00  5:00pm. The basic setting is a round robin followed by direct elimination rounds concluded by a little final and the big final. Depending on the total number of players, teams will consist of 57 players and games will last between 10 and 20 minutes. In total we are hoping for 6 to 8 teams. The exact time and format (teams and game plan) will be decided over the next couple of weeks before the conference, according to the number of participants and their properties. A priori, teams will correspond to thematics:
 Loop gravity & canonical techniques
 Spinfoams & GFT
 Cosmology & LQC
 CDT & Shape dynamics
 QG phenomenology
 BHs & Thermodynamics of GR
 Strings & CFT
Players wanting to qualify to a specific thematic team should provide a proof of research in that thematic (no need of anything formal). To register for the cup please send an email to [email protected] with your name, preferred thematic(s), birth country and institution (these last two will be needed in case it is finally decided to switch back to the original national team format.) If you have other questions, please direct them to Etera Livine or Florian Girelli. There will likely be a Perimeter Institute / conference staff team if enough participants are interested. Comments and suggestions may be included in the text of your registration email or may be posted to the facebook event webpage:https://www.facebook.com/events/188604221300066/?ref=14 If you want to play, please think about bringing a white tshirt and a black tshirt, and appropriate footwear to play on grass. Games will be selfrefereed, with ultimate decision residing with the organizers. Water and fruit will be provided.
 Giovanni AmelinoCamelia, La Sapienza University of Rome
 Abhay Ashtekar, Pennsylvania State University
 Fernando Barbero, Instituto de Estructura de la Materia
 John Barrett, University of Nottingham
 James Bjorken, SLAC
 Martin Bojowald, Pennsylvania State University
 Robert Brandenberger, McGill University
 Alejandro Corichi, Pennsylvania State University
 Fay Dowker, Imperial College, London
 Rodolfo Gambini, Instituto de Fisica Facultad de Ciendias
 Steve Giddings, University of California, Santa Barbara
 Viqar Husain, University of New Brunswick
 Ted Jacobson, University of Maryland
 Kirill Krasnov, University of Nottingham
 Jerzy Lewandowski, University of Warsaw
 Stefano Liberati, SISSA
 Etera Livine, Ens de Lyon
 Renate Loll, Radbud University Nijmegen
 Yongge Ma, Beijing Normal University
 Joao Magueijo, Imperial College, London
 Alex Maloney, McGill University
 Matilde Marcolli, California Institute of Technology
 Guillermo Mena, Instituto de Estructura de la Materia
 Djordje Minic, Virginia Tech
 Daniele Oriti, Albert Einstein Institute
 Roberto Percacci, SISSA
 Alejandro Perez, Centre de Physique Theorique
 Jorge Pullin, Lousiana State University
 Martin Reuter, Johannes Gutenberg Universitat
 Vincent Rivasseau, Laboratoire de Physique Théorique d'Orsay
 Carlo Rovelli, Centre de Physique Theorique
 Thomas Thiemann, University of ErlangenNuernberg
 William Unruh, University of British Columbia
 Joseph Ben Geloun, Perimeter Institute
 Eugenio Bianchi, Perimeter Institute
 Valentin Bonzom, Perimeter Institute
 Bianca Dittrich, Perimeter Institute
 Astrid Eichhorn, Perimeter Institute
 Cecilia Flori, Perimeter Institute
 Laurent Freidel, Perimeter Institute
 Steffen Gielen, Perimeter Institute
 Florian Girelli, Perimeter Institute & University of Waterloo
 Philipp Hoehn, Perimeter Institute
 Mercedes MartinBenito, Perimeter Institute
 Flavio Mercati, Perimeter Institute
 Lee Smolin, Perimeter Institute
Guest Speakers: Ground transportation arrangements will be made on your behalf and instructions sent prior to your arrival. If you need transportation while attending the conference, we offer suggestions below. If flying, we suggest that you book your flight to arrive atToronto International Airport (YYZ) or the Region of Waterloo International Airport (YKF).
Boulevard Limousine (estimated travel time 1hr) The fare for Boulevard Limousine for one passenger is $118.00 to the Toronto Airport. The fare for one passenger from the Toronto Airport to Waterloo is $133.00. To make reservations, please visit their website or call 5198868090.
Airways Transit (estimated travel time 1hr) Airways Transit connects Toronto (Pearson), Hamilton (Munro), and Region of Waterloo International Airports with the KitchenerWaterloo area by providing 24 hour shared ride doortodoor service. For Toronto Pearson airport we have obtained a reduced conference fare of $58.00 per person, one way, tax included. To receive the reduced fare you must book in advance and identify yourself as a LOOPS 13 delegate. To make reservations online: http://conferences.airwaystransit.com Enter booking code LOOPS 13 (enter exactly as shown) By phone 24 hours: 5198862121 Please identify yourself as a LOOPS 13 delegate.
0001 Toronto Cabs (estimated travel time 1hr) Fixed $190.00 rate for oneway: Toronto International Airport to Waterloo. Call 4168095656. Waterloo Taxi (estimated travel time 1hr) Fixed $76.50 rate for oneway: Waterloo to Toronto International Airport. Call 5198861200. Note: One or more passengers can split this $90.00 flat rate.
Car Rentals Upon arrival in any of the terminals at Pearson International Airport there are a number of car rental agencies to choose from. Their booths are located on the arrivals level. The cost of a car rental is dependent upon the type of vehicle you would like and the length of the stay. Driving Directions
 From the airport, follow signs for Highway 427 South/Highway 401.
 Continue to follow signs for Highway 401 West  London.
 Proceed West on Highway 401.
 Exit Highway 401 at Highway 8 West.
 Take exit 278 (Highway 8 West) and follow 8 West for 5 km to Highway 85, towards Highway 7 East.
 Proceed on Highway 85 for 5 km to Bridgeport Road exit. Turn right at the offramp, traveling west.
 Follow Bridgeport Road for 2 km into downtown Waterloo.
 Bridgeport is a fourlane oneway road. It becomes Caroline Street at Albert Street. Continue straight ahead.
 Travel forward another 200 metres, but ease over into the righthand lane. As you go down a hill and around a curve, look for the green Perimeter Institute sign on the right hand side. The parking lot entrance is just after the sign (past the historic grist mill that sits on the edge of Silver Lake).
 Turn right into the PI parking lot entrance.
If you are planning on driving to PI, please arrive 20 minutes early to allow time for you to obtain a shortterm parking pass from reception and to park your car in the appropriate lot. This shortterm pass will allow you to park for the duration of the conference at the Bauer Parking lot on Father David Bauer Drive across the street from the Waterloo Recreation Complex.
Mixed Session
Quantum Cosmology  5
Quantum Foundations  2
Renormalization  3
Canonical Quantum Gravity and Spin Foams
Discrete Approaches and Mixed Session
Quantum Cosmology  4
Quantum Foundations  1
Promising Paths: What Have We Learned So Far About Quantum Gravity?
In LQG we work in the spirit of Antonio Machado: "Traveler, there is no path; Paths are made by walking." I will present a bird's eye view of some of the paths that have emerged since Loops 11 and offer a few suggestions.
I try to make the point about what we know and what we do not yet know about the possibility of writing a quantum theory of gravity.
Scenes From Polymer Quantization
A regime of "polymer quantum field theory on curved spacetime" should emerge in a low energy approximation of quantum gravity based on LQG ideas. This era should be characterized by a polymer scale, and give modifications to the usual semiclassical approximation. I will describe work on gravitational collapse, cosmology, and statistical mechanics in this setting. Results include models of horizon evaporation, inflation and graceful exit without an inflaton potential, and an indication of dimensional reduction from 4 to 2.5 dimensions.