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We compute the regularized temperature for a spacetime foam model, consisting on S^4 instantons, in quantum gravity. Assuming that thermal equilibrium takes place with some amount of radiation - with thermal fields in the SU(2)xU(1) gauge theory - we obtain the remarkable result that the squared value of this temperature exactly coincides with the electroweak coupling constant at the energy scale of the gauge bosons W. This is consistent with the classical ADM result that the electrical charge should be equal to its finite gravitational self energy.
The goal of this paper is to introduce a systematic approach to spin foams. We define operator spin foams, that is foams labelled by group representations and operators, as the main tool. An equivalence relation we impose in the set of the operator s
The canonical ``loop formulation of quantum gravity is a mathematically well defined, background independent, non perturbative standard quantization of Einsteins theory of General Relativity. Some among the most meaningful results of the theory are:
The Lorentzian Engle-Pereira-Rovelli-Livine/Freidel-Krasnov (EPRL/FK) spinfoam model and the Conrady-Hnybida (CH) timelike-surface extension can be expressed in the integral form $int e^S$. This work studies the analytic continuation of the spinfoam
In the Kaluza-Klein model with a cosmological constant and a flux, the external spacetime and its dimension of the created universe from a $S^s times S^{n-s}$ seed instanton can be identified in quantum cosmology. One can also show that in the intern
Small violations of spacetime symmetries have recently been identified as promising Planck-scale signals. This talk reviews how such violations can arise in various approaches to quantum gravity, how the emergent low-energy effects can be described w