A Spinor Theory of Gravity and the Cosmological Framework

Recently we have presented a new formulation of the theory of gravity based on an implementation of the Einstein Equivalence Principle distinct from General Relativity. The kinetic part of the theory - that describes how matter is affected by the modified geometry due to the gravitational field - is the same as in General Relativity. However, we do not consider the metric as an independent field. Instead, it is an effective one, constructed in terms of two fundamental spinor fields $\Psi$ and $\Upsilon$ and thus the metric does not have a dynamics of its own, but inherits its evolution through its relation with the fundamental spinors. In the first paper it was shown that the metric that describes the gravitational field generated by a compact static and spherically symmetric configuration is very similar to the Schwarzschild metric. In the present paper we describe the cosmological framework in the realm of the Spinor Theory of Gravity

The mass of the graviton and the cosmological constant

We show that the graviton acquires a mass in a de Sitter background given by $m_{g}^{2}=-{2/3}\Lambda.$ This is precisely the fine-tuning value required for the perturbed gravitational field to mantain its two degrees of freedom.Comment: Title changed and few details added, without any changes in the conclusio

La Geometria come filo di Arianna: note di approfondimento sul rapporto ideazione-costruzione della più grande cupola di forma ovata del mondo

La cupola del Santuario di Vicoforte in Piemonte costituisce un'opera di particolare complessità costruttiva sia per le sue dimensioni sia per la sua forma: è infatti la più grande cupola ovata in muratura nel mondo. Questo studio riguarda la genesi geometrica della costruzione delle cupola, ed evidenzia che la cupola costruita è, da un punto di vista dei parametri geometrici, alquanto diversa da quella disegnata nei progetti. La ricerca è focalizzata sull'analisi geometrica delle sezioni verticali della cupola, al fine indagare il profilo delle centine usate nella costruzione. I risultati possono consentire una più attillata definizione dei modelli di simulazione del comportamento strutturale e sismico che sono necessari per la conservazione dell'integrità del manufatto. The dome of the Sanctuary of Vicoforte, the largest oval masonry dome in the world, is an exceptional expression of building technique for its shape and dimension. This study wants to add information about the geometrical conception of the dome using the modern modeling possibilities based on recent laser scanner survey. In particular it integrates the analysis of the archival drawings and the 3D survey of the dome in order to investigate the geometrical shape of the temporary centrings used in the dome construction. Improving the knowledge about the tridimensional shape and the construction techniques of such dome is of crucial importance at the moment, because the Sanctuary is the subject of a structural monitoring and research campaign due to the important settlements and cracking fenomena that affect the buildin

The cosmological dependence of weak interactions

A model for the cosmological time dependence of weak interactions is discused and some experimental tests suggested

A Note on the Local Cosmological Constant and the Dark Energy Coincidence Problem

It has been suggested that the Dark Energy Coincidence Problem could be interpreted as a possible link between the cosmological constant and a massive graviton. We show that by using that link and models for the graviton mass a dark energy density can be obtained that is indeed very close to measurements by WMAP. As a consequence of the models, the cosmological constant was found to depend on the density of matter. A brief outline of the cosmological consequences such as the effect on the black hole solution is given