Horndeski: beyond, or not beyond?

Exploring gravitational theories beyond Horndeski

We have recently proposed a new class of gravitational scalar-tensor theories free from Ostrogradski instabilities, in Ref. [1]. As they generalize Horndeski theories, or “generalized” galileons, we call them G. These theories possess a simple formulation when the time hypersurfaces are chosen to coincide with the uniform scalar field hypersurfaces. We confirm that they contain only three propa...

Observational signatures of the theories beyond Horndeski

In the approach of the effective field theory of modified gravity, we derive the equations of motion for linear perturbations in the presence of a barotropic perfect fluid on the flat isotropic cosmological background. In a simple version of Gleyzes-Langlois-Piazza-Vernizzi (GLPV) theories, which is the minimum extension of Horndeski theories, we show that a slight deviation of the tensor propa...

Tumour radiobiology beyond fractionation

Historically it has been shown repeatedly that single high doses of radiation do not allow a therapeutic differential between tumor and critical normal tissues but dose fractionation does. The purpose of conventional dose fractionation is to increase dose to the tumor while preserving normal tissue function. Tumors are generally irradiated with 2Gy dose per fraction delivered daily to a more or...

Gilles Deleuze: Beyond Peirce’s Semiotics

This paper studies the role of the semiotic discussions of Charles Sanders Peirce, the American philosopher and mathematician, in the formation of Deleuze’s first leading book on cinema, Cinema 1: the Movement-Image,in whichthe author surpasses Peirce’s semiotics. We will show how Deleuze creates a new form of signs in his second leading book on cinema, Cinema 2: the Time-Image. Deleuze had tri...

Like it or not, life-extension research extends beyond biogerontology.