Related papers: Time variation of fundamental couplings and dynami…
We consider stochastically quantized self-interacting scalar fields as suitable models to generate dark energy in the universe. Second quantization effects lead to new and unexpected phenomena is the self interaction strength is strong. The…
The two dark sectors of the universe - dark matter and dark energy - may interact with each other. Background and linear density perturbation evolution equations are developed for a generic coupling. We then establish the general conditions…
The presence of a dynamical scalar field in the early universe could significantly affect the `freeze-out' time of particle species. In particular, it was recently shown that an enhancement of the relic abundance of neutralinos can be…
We investigate the late-time evolution of the Universe within a cosmological model in which dark matter and dark energy are identified with two interacting scalar fields. Using methods of qualitative analysis of dynamical systems, we…
A coupling between a scalar field (representing the dark energy) and dark matter could produce rich phenomena in cosmology. It affects cosmic structure formation mainly through the fifth force, a velocity-dependent force that acts parallel…
The dynamical properties of a model of dark energy in which two scalar fields are coupled by a non-canonical kinetic term are studied. We show that overall the addition of the coupling has only minor effects on the dynamics of the two-field…
Astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of…
Scalar fields in the early Universe are mostly discussed in two limits: either in equilibrium or completely decoupled. In this work we discuss scenarios where there are scalar fields that are not in equilibrium, but for which the coupling…
We present a complete numerical study of cosmological models with a time dependent coupling between the dark energy component driving the present accelerated expansion of the Universe and the Cold Dark Matter (CDM) fluid. Depending on the…
Under the assumption that the variations of parameters of nature and the current acceleration of the universe are related and governed by the evolution of a single scalar field, we show how information can be obtained on the nature of dark…
In this paper we discuss a possible cosmological time evolution of fundamental constants from the theoretical and experimental point of views. On the theoretical side, we explain that such a cosmological time evolution is actually something…
Crossover quintessence predicts that the time variation of fundamental couplings is substantially faster at redshift $z\approx 2$ than over the past few billion years. This could reconcile the reported time variation of the fine structure…
The cosmological evolution of a quintessence-like scalar field, phi, coupled to matter and gauge fields leads to effective modifications of the coupling constants and particle masses over time. We analyze a class of models where the scalar…
In this talk, I have discussed the implications of a multi-component nature of cosmic Dark Matter for the observational bounds on possible long-range fifth-forces mediated by a Dark Energy scalar field. By assuming a simple internal…
The aim of this paper is to derive limits on various forms of ``new physics'' using atomic experimental data. Interactions with dark energy and dark matter fields can lead to space-time variations of fundamental constants, which can be…
We compute the time variation of the fundamental constants (such as the ratio of the proton mass to the electron mass, the strong coupling constant, the fine structure constant and Newton's constant) within the context of the so-called…
We describe scalar-bimetric theories where the dynamics of the Universe are governed by two separate metrics, each with an Einstein-Hilbert term. In this setting, the baryonic and dark matter components of the Universe couple to metrics…
We propose a general model where quintessence couples to electromagnetism via its kinetic term. This novelty generalizes the linear dependence of the gauge kinetic function on $\phi$, commonly adopted in the literature. The interaction…
The cosmological dynamics of minimally coupled scalar field that couple to the background matter with thermal interactions is investigated in exponential potential. The conditions for the existence and stability of various critical points…
Dark energy and dark matter are the dominant sources in the evolution of the late universe. They are currently only indirectly detected via their gravitational effects, and there could be a coupling between them without violating…