We discuss a possibility that our electroweak vacuum is absolutely stable even if the top Yukawa coupling is larger than the critical value. Such a scenario can be realized without introducing new particles if we adopt a renormalization prescription which respects the asymptotic scale invariance at the quantum level. Instead, the theory becomes non-renormalizable and the perturbative unitarity...
The recent GW170817 measurement favors the simplest Dark Energy models, such as a single scalar field. Quintessence models can be classified in two classes, freezing and thawing, depending on whether the equation of state decreases towards −1 or departs from it. In this work we put observational constraints on the parameters governing the equations of state of tracking freezing, scaling...