Related papers: Bifurcated symmetry breaking in scalar-tensor grav…
We solve analytically and numerically the generalized Einstein equations in scalar-tensor cosmologies to obtain the evolution of dark energy and matter linear perturbations. We compare our results with the corresponding results for…
We consider a hidden sector with a vectorlike confining gauge theory like QCD with $N_{h,c}$ colors and $N_{h,f}$ light quarks ${\cal Q}_h$ in the hidden sector. Then a scale $\Lambda_H$ would be generated by dimensional transmutation, and…
Popular extensions of the standard model of particle physics feature new fields and symmetries which could, for example, dynamically generate neutrino masses from $B-L$ spontaneous symmetry breaking. If a new light scalar that decays into…
We analyse the (thermo)dynamics of the scalar degrees of freedom in the scalar boson stars through the dark matter density under extreme conditions. The boson stars are studied in terms of a dark scalar sector in such a way this sector…
We propose a new UV-complete dark energy model which is \underbar{\it neither} a cosmological constant nor a slowly rolling scalar field. Our dark energy is the flux of a top form in a hidden sector gauge theory similar to QCD. The top form…
The dark side of the universe is mysterious and its nature is still unknown. In fact, this poses perhaps as the biggest challenge in the modern cosmology. The two components of the dark sector (dark matter and dark energy) correspond today…
Previous quantum field estimations of the QCD vacuum in the expanding space-time lead to a dark energy component scaling linearly with the Hubble parameter, which gives the correct figure for the observed cosmological term. Here we show…
A new strong interaction sector is proposed as a possible origin for the Dark Energy and Dark matter. It is described by an unbroken gauge group $SU(2)_Z$ which grows strong at a scale $\Lambda_Z \sim 10^{-3} eV$ provided its coupling is of…
We consider cosmological aspects of the Dark Dimension (a mesoscopic dimension of micron scale), which has recently been proposed as the unique corner of the quantum gravity landscape consistent with both the Swampland criteria and…
We suggest that non-trivial correlations between the dark matter particle mass and collider based probes of missing transverse energy H_T^miss may facilitate a two tiered approach to the initial discovery of supersymmetry and the subsequent…
We describe a new type of gravity-matter models where gravity couples in a non-conventional way to two distinct scalar fields providing a unified Lagrangian action principle description of: (a) the evolution of both "early" and "late"…
In the present universe visible and dark matter contribute comparable energy density although they have different properties. This coincidence can be elegantly explained if the dark matter relic density, originating from a dark matter…
In this work we construct a unified model of dark energy and dark matter. This is done with the following three elements: a gravitating scalar field, phi with a non-conventional kinetic term, as in the string theory tachyon; an arbitrary…
I present cosmological arguments which point towards a Horava-Witten like picture of the universe, with the unification scale of order the fundamental gravitational scale. The SUSY breaking scale is determined by the dynamics of gauge…
We propose a classically scale invariant extension of the Standard Model where the electroweak symmetry breaking and the mass of the Dark Matter particle come from the common scale. We introduce $U(1)_X$ gauge symmetry and $X$-charged…
A matter-coupled scalar field model is presented in obtaining a scalar fifth force when the constraint of the current cosmological constant is satisfied. The interaction potential energy density between the scalar field and matter has a…
Dark matter and dark energy are dominating components of the Universe. Their presence affects the course and results of processes, which are driven by the gravitational interaction. The objective of the paper was to examine the influence of…
It is proposed that the recently announced BICEP2 value of tensor-to scalar ratio $r\sim0.2$ can be explained as containing an extra contribution from the recent acceleration of the universe. In fact this contribution, being robust, recent…
It is well known that global symmetries protect local supersymmetry and a zero value for the cosmological constant in no--scale supergravity. The breakdown of these symmetries, which ensure the vanishing of the vacuum energy density,…
The mystery of the Dark energy is not just its smallness. The extreme fine tuning of its density in the Early Universe such that it permits galaxy formation before creating a new inflationary epoch is its other unexplained aspect. Here we…