


Quantum Geometry and Quantum Gravity
Research Networking Programme of the European
Science Foundation 
2^{nd} School and Workshop on
Quantum Gravity and Quantum Geometry
September 1320, 2009



Network Homepage: 
www.maths.nottingham.ac.uk/qg/


Organizing Committee: 
J. Barrett 
H. Grosse 
L. Jonke 
G. Zoupanos 



We organize an intensive oneweek School on Quantum
Gravity and related topics in Corfu from Sunday 13 th (registration
date) till Sunday 20 th of September 2009 (departure date). It will
provide an upto date introduction to some of the main research topics
of the Quantum Geometry and Quantum Gravity ESF Network, including
loop quantum gravity, supergravity, renormalization theory, higher
gauge theories and quantum spaces. A series of Workshoptype seminars
by international experts will provide a link to current
research. 
 
School main lecturers and topics: 
 Prof. Abhay Ashtekar
Title: Loop Quantum Gravity
Abstract
This set of lectures will provide an introduction to loop quantum
gravity through the simpler setting of loop quantum cosmology. The
goal will be to provide a concise summary of the conceptual
framework, salient results and open issues. The time limitation will
not permit me to give detailed proofs and technical details for
which I will provide a guide to literature.
Table of Contents
 Background independence and nonperturbative methods.
 General relativity in terms of connection variables.
 Loop quantum cosmology: Kinematics.
 Loop quantum cosmology: Dynamics.
 Principal results and open problems of loop quantum gravity.
 Prof. John Baez
Title: Categorification in Fundamental Physics
Abstract
Categorification is the process of replacing setbased mathematics
with analogous mathematics based on categories or ncategories. In
physics, categorification enters naturally as we pass from the
mechanics of particles to higherdimensional field theories. For
example, higher gauge theory is a generalization of gauge theory
that describes the parallel transport not just of particles, but
also strings or higherdimensional branes. To handle strings, we
must categorify familiar notions from gauge theory and consider
connections on "principal 2bundles" with a given "structure
2group". One of the simplest 2groups is the shifted version of
U(1). U(1) gerbes are really principal 2bundles with this
structure 2group, and the B field in string theory can be seen as a
connection on this sort of 2bundle. The relation between U(1)
bundles and symplectic manifolds, so important in the geometric
quantization, extends to a relation between U(1) gerbes and
"2plectic manifolds", which arise naturally as phase spaces for
2dimensional field theories, such as the theory of a classical
string. More interesting 2groups include the "string 2group"
associated to a compact simple Lie group G. This is built using the
central extension of the loop group of G. A closely related 3group
plays an important role in ChernSimons theory, and it appears that
ngroups for higher n are important in the study of
higherdimensional membranes.
Table of Contents
 Connections on abelian gerbes.
 Lie ngroups and Lie nalgebras.
 Multisymplectic geometry and classical field theory.
 Higher gauge theory, strings and branes.
 Prof. John Barrett
Title: Spin networks and quantum gravity
Abstract
The series of lectures will be devoted to explaining techniques of spin networks and outlining their use in models of quantum spacetime and quantum gravity. The lectures will start with the
classical SU(2) spin networks, explaining the diagrammatical techniques and the construction of the PonzanoRegge model of 3d quantum gravity. Then the qdeformation of spin networks and the TuraevViro model are constructed, together with an explanation of the completion to a topological quantum field theory. Next, observables are introduced in these models, and some related models of quantum spacetime are also mentioned. Finally, there will be an introduction to some fourdimensional models, both the topological ones, and, briefly, an outline of four dimensional gravity models.
 Prof. Vincent Rivasseau
Title: Renormalization in Fundamental Physics
Abstract
Renormalization was first invented to cure the short distance
singularities in quantum field theory. Simultaneously constructive
field theory developed combinatoric tools to also attack the
neglected divergence of perturbation theory. It was later understood
that the renormalization group is the correct tool to track the
change of physical phenomena under change of observation scale. Then
it was realized that the correct notion of scale is not always
naively related to short or long distance phenomena, but rather to
the spectrum of the propagator. This allowed in the recent years to
understand how to renormalize noncommutative field theory, and to
attack with a fresh look and new hopes the problem of renormalizing
quantum gravity.
Table of contents
 Renormalization in ordinary QFT.
 Constructive Field Theory Primer.
 Noncommutative Field Theory.
 Noncommutative Renormalization.
 Towards renormalizing Quantum Gravity.
 Prof. Carlo Rovelli
Title: Covariant loop quantum gravity and its lowenergy
limit
Abstract and content (*)
I present a new look on Loop Quantum Gravity, aimed at giving a
better grasp on its dynamics and its lowenergy limit. Following the
highly succesfull model of QCD, general relativity is quantized by
discretizing it on a finite lattice, quantizing, and then studying
the continuous limit of expectation values. The quantization can be
completed, and two remarkable theorems follow. The first gives the
equivalence with the kinematics of canonical Loop Quantum Gravity.
This amounts to an independent rederivation of all well known Loop
Quantum gravity kinematical results. The second the equivalence of
the theory with the Feynman expansion of an auxiliary field theory.
Observable quantities in the discretized theory can be identifies
with general relativity npoint functions in appropriate regimes.
The continuous limit turns out to be subtly different than that of
QCD, for reasons that can be traced to the general covariance of the
theory. I discuss this limit, the scaling properties of the theory,
and I pose the problem of a renormalization group analysis of its
large distance behavior.
* tentative




The main speakers of the workshop
include. 

 Paolo Aschieri
 Glenn Barnich
 Maja Buric
 Leonardo Castellani
 ChongSan Chu
 Brian Dolan
 Michel DuboisViolette
 Steven Giddings
 Kristina Giesel
 Harald Grosse
 Jerzy Lewandowski
 Fedele Lizzi
 Jerzy Lukierski
 John Madore
 Shahn Majid
 Catherine Meusburger
 Denjoe O'Connor
 Martin Reuter
 Peter Schupp
 Harold Steinacker
 Richard Szabo
 Satoshi Watamura



Program: 
Lectures+Workshop
(doc)
(pdf)


Meeting Location 
MonRepos, Corfu, Greece
(map  zoom out to see larger
area) 

