Simone Speziale

Numerical evidence of regularized correlations in spin foam gravity (2007)

We consider stability under evolution as a criterion to select a physical boundary state for the spinfoam formalism. As an example, we apply it to the simplest spinfoam defined by a single quantum...

Christensen, J. Daniel, Livine, Etera R., Speziale, Simone

We report on the numerical analysis of the area correlations in spin foam gravity on a single 4-simplex considered by Rovelli in PRL 97 (2006) 151301. We compare the asymptotics and confirm the...

Consistently Solving the Simplicity Constraints for Spinfoam Quantum Gravity (2007)

Linearized dynamics from the 4-simplex Regge action (2007)

We give an independent derivation of the Engle-Pereira-Rovelli spinfoam model for quantum gravity which recently appeared in [arXiv:0705.2388]. Using the coherent state techniques introduced earlier...

Dittrich, Bianca, Freidel, Laurent, Speziale, Simone

We study the relation between the hessian matrix of the riemannian Reggae action on a 4-simplex and linearized quantum gravity. We give an explicit formula for the hessian as a function of the...

Coupling gauge theory to spinfoam 3d quantum gravity (2007)

Speziale, Simone

We construct a spinfoam model for Yang-Mills theory coupled to quantum gravity in three dimensional riemannian spacetime. We define the partition function of the coupled system as a power series in...

A new spinfoam vertex for quantum gravity (2007)

Graviton propagator in loop quantum gravity (2007)

We introduce a new spinfoam vertex to be used in models of 4d quantum gravity based on SU(2) and SO(4) BF theory plus constraints. It can be seen as the conventional vertex of SU(2) BF theory, the...

Bianchi, Eugenio, Modesto, Leonardo, Rovelli, Carlo, Speziale, Simone

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.

A semiclassical tetrahedron (2007)

Grasping rules and semiclassical limit of the geometry in the Ponzano-Regge model (2006)

We construct a macroscopic semiclassical state state for a quantum tetrahedron. The expectation values of the geometrical operators representing the volume, areas and dihedral angles are peaked...

Hackett, Jonathan, Speziale, Simone

We show how the expectation values of geometrical quantities in 3d quantum gravity can be explicitly computed using grasping rules. We compute the volume of a labelled tetrahedron using the triple...

Group Integral Techniques for the Spinfoam Graviton Propagator (2006)

A semiclassical tetrahedron (2006)

We consider the proposal of gr-qc/0508124 for the extraction of the graviton propagator from the spinfoam formalism. We propose a new ansatz for the boundary state, using which we can write the...

Towards the graviton from spinfoams: higher order corrections in the 3d toy model (2006)

We construct a macroscopic semiclassical state state for a quantum tetrahedron. The expectation values of the geometrical operators representing the volume, areas and dihedral angles are peaked...

Livine, Etera R., Speziale, Simone, Willis, Joshua L.

We consider the recent calculation gr-qc/0508124 of the graviton propagator in the spinfoam formalism. Within the 3d toy model introduced in gr-qc/0512102, we test how the spinfoam formalism can be...

On the perturbative expansion of a quantum field theory around a topological sector (2006)

Graviton propagator in loop quantum gravity (2006)

The idea of treating general relativistic theories in a perturbative expansion around a topological theory has been recently put forward in the quantum gravity literature. Here we investigate the...

Bianchi, Eugenio, Modesto, Leonardo, Rovelli, Carlo, Speziale, Simone

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.

From 3-geometry transition amplitudes to graviton states (2006)

Mattei, Federico, Rovelli, Carlo, Speziale, Simone, Testa, Massimo

In various background independent approaches, quantum gravity is defined in terms of a field propagation kernel: a sum over paths interpreted as a transition amplitude between 3-geometries, expected...

Graviton propagator in loop quantum gravity (2006)

Bianchi, Eugenio, Modesto, Leonardo, Rovelli, Carlo, Speziale, Simone

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 (2006)

Bianchi, Eugenio, Modesto, Leonardo, Rovelli, Carlo, Speziale, Simone

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.

From 3-geometry transition amplitudes to graviton states (2006)

Mattei, Federico, Rovelli, Carlo, Speziale, Simone, Testa, Massimo

In various background independent approaches, quantum gravity is defined in terms of a field propagation kernel: a sum over paths interpreted as a transition amplitude between 3-geometries, expected...

From 3-geometry transition amplitudes to graviton states (2006)

Mattei, Federico, Rovelli, Carlo, Speziale, Simone, Testa, Massimo

In various background independent approaches, quantum gravity is defined in terms of a field propagation kernel: a sum over paths interpreted as a transition amplitude between 3-geometries, expected...

From 3-geometry transition amplitudes to graviton states (2006)

Mattei, Federico, Rovelli, Carlo, Speziale, Simone, Testa, Massimo

In various background independent approaches, quantum gravity is defined in terms of a field propagation kernel: a sum over paths interpreted as a transition amplitude between 3-geometries, expected...

Towards the graviton from spinfoams: the 3d toy model (2005)

Speziale, Simone

Recently, a proposal has appeared for the extraction of the 2-point function of linearised quantum gravity, within the spinfoam formalism. This relies on the use of a boundary state, which introduces...

On the perturbative expansion of a quantum field theory around a topological sector (2005)

From 3-geometry transition amplitudes to graviton states (2005)

The idea of treating general relativistic theories in a perturbative expansion around a topological theory has been recently put forward in the quantum gravity literature. Here we investigate the...

Mattei, Federico, Rovelli, Carlo, Speziale, Simone, Testa, Massimo

In various background independent approaches, quantum gravity is defined in terms of a field propagation kernel: a sum over paths interpreted as a transition amplitude between 3-geometries, expected...

Spinfoam 2d quantum gravity and discrete bundles (2005)

Reconcile Planck-scale discreteness and the Lorentz-Fitzgerald contraction (2005)

In 4 dimensions, general relativity can be formulated as a constrained BF theory; we show that the same is true in 2 dimensions. We describe a spinfoam quantization of this constrained BF-formulation...

On the perturbative expansion of a quantum field theory around a topological sector (2005)

A Planck-scale minimal observable length appears in many approaches to quantum gravity. It is sometimes argued that this minimal length might conflict with Lorentz invariance, because a boosted...

On the perturbative expansion of a quantum field theory around a topological sector (2005)

The idea of treating general relativistic theories in a perturbative expansion around a topological theory has been recently put forward in the quantum gravity literature. Here we investigate the...

Spinfoam 2d quantum gravity and discrete bundles (2004)

The idea of treating general relativistic theories in a perturbative expansion around a topological theory has been recently put forward in the quantum gravity literature. Here we investigate the...

Spinfoam 2d quantum gravity and discrete bundles (2004)

In 4 dimensions, general relativity can be formulated as a constrained $BF$ theory; we show that the same is true in 2 dimensions. We describe a spinfoam quantization of this constrained...

Spinfoam 2d quantum gravity and discrete bundles (2004)

In 4 dimensions, general relativity can be formulated as a constrained BF theory; we show that the same is true in 2 dimensions. We describe a spinfoam quantization of this constrained BF-formulation...

Reconcile Planck-scale discreteness and the Lorentz-Fitzgerald contraction (2002)

In 4 dimensions, general relativity can be formulated as a constrained BF theory; we show that the same is true in 2 dimensions. We describe a spinfoam quantization of this constrained BF-formulation...

Reconcile Planck-scale discreteness and the Lorentz-Fitzgerald contraction (2002)

A Planck-scale minimal observable length appears in many approaches to quantum gravity. It is sometimes argued that this minimal length might conflict with Lorentz invariance, because a boosted...

Reconcile Planck-scale discreteness and the Lorentz-Fitzgerald contraction (2002)

A Planck-scale minimal observable length appears in many approaches to quantum gravity. It is sometimes argued that this minimal length might conflict with Lorentz invariance, because a boosted...