author={Florian Conrady and Carlo Rovelli},
  journal={International Journal of Modern Physics A},
We investigate the idea of a "general boundary" formulation of quantum field theory in the context of the Euclidean free scalar field. We propose a precise definition for an evolution kernel that propagates the field through arbitrary space–time regions. We show that this kernel satisfies an evolution equation which governs its dependence on deformations of the boundary surface and generalizes the ordinary (Euclidean) Schrodinger equation. We also derive the classical counterpart of this… 
From the discrete to the continuous: towards a cylindrically consistent dynamics
Discrete models usually represent approximations to continuum physics. Cylindrical consistency provides a framework in which discretizations exactly mirror the continuum limit. As a standard tool for
On the Covariant Hamilton-Jacobi Equation for the Teleparallel Equivalent of General Relativity
The covariant Hamilton-Jacobi equation for the Teleparallel Equivalent of General Relativity is derived based on the analysis of constraints within the De Donder-Weyl covariant Hamiltonian theory
Spin foam propagator: A new perspective to include the cosmological constant
In recent years, the calculation of the first non-vanishing order of the metric 2-point function or graviton propagator in a semiclassical limit has evolved as a standard test for the credibility of
Holomorphic quantization of linear field theory in the general boundary formulation
We present a rigorous quantization scheme that yields a quantum field theory in general boundary form starting from a linear field theory. Following a geometric quantization approach in the Kahler
Second-order amplitudes in loop quantum gravity
We explore some second-order amplitudes in loop quantum gravity. In particular, we compute some second-order contributions to diagonal components of the graviton propagator in the large distance
0 60 40 44 v 2 1 3 M ay 2 00 6 Graviton propagator in loop quantum gravity
We compute some components of the graviton propagator in loop quantum gravity, using the spinfoam formalism, up to some second order terms in the expansion parameter.
Graviton propagator in loop quantum gravity
We compute some components of the graviton propagator in loop quantum gravity, using the spinfoam formalism, up to some second-order terms in the expansion parameter.
Semiclassical analysis of loop quantum gravity
In this Ph.D. thesis, we explore and develop new methods that should help in determining an effective semiclassical description of canonical loop quantum gravity and spin foam gravity. A brief


Minkowski vacuum in background independent quantum gravity
We consider a local formalism in quantum field theory, in which no reference is made to infinitely extended spacial surfaces, infinite past or infinite future. This can be obtained in terms of a
Schrödinger's cat and the clock: lessons for quantum gravity
I review basic principles of the quantum mechanical measurement process in view of their implications for a quantum theory of general relativity. It turns out that a clock as an external classical
Spin Foam Models for Quantum Gravity
In this topical review, we review the present status of the spin foam formulation of non-perturbative (background-independent) quantum gravity. The topical review is divided into two parts. In the
Quantum Gravity
General lectures on quantum gravity. 1 General Questions on Quantum Gravity It is not clear at all what is the problem in quantum gravity (cf. [3] or [8] for general reviews, written in the same
Introduction to Modern Canonical Quantum General Relativity
This is an introduction to the by now fifteen years old research field of canonical quantum general relativity, sometimes called "loop quantum gravity". The term "modern" in the title refers to the
  • Progr. Phys. 64, 1489
  • 2001
State sum models for quantum gravity
This paper reviews the construction of quantum field theory on a 4-dimensional spacetime by combinatorial methods, and discusses the recent developments in the direction of a combinatorial
Topological quantum field theories
Following my plenary lecture on ICMP2000 I review my results concerning two closely related topics: topological quantum field theories and the problem of quantization of gauge theories. I start with
An Introduction to spin foam models of quantum gravity and BF theory
In loop quantum gravity we now have a clear picture of the quantum geometry of space, thanks in part to the theory of spin networks. The concept of ‘spin foam’ is intended to serve as a similar