Related papers: Laboratory search for a quintessence field
One possibility to explain the current accelerated expansion of the universe may be related with the presence of cosmologically evolving scalar whose mass depends on the local matter density (chameleon cosmology). We point out that matter…
Current cosmological data seem to show that dark energy is evolving in time and that it possibly crossed the phantom divide in the past. So far the only theories that lead to such a behavior involve a non-trivial coupling between dark…
We investigate the cosmological implications of a new class of modified gravity, where the field equations generically include higher-order derivatives of the matter fields, arising from the introduction of non-dynamical auxiliary fields in…
An oscillating scalar field can behave like cold dark matter in the expanding Universe. In relativistic cosmology, this perspective is primarily reasoned by an evolution of a background scalar field and its subhorizon perturbations in a…
We investigate the clustering properties of a dynamical dark energy component. In a cosmic mix of a pressureless fluid and a light scalar field, we follow the linear evolution of spherical matter perturbations. We find that the scalar field…
The dynamics of expansion of the Universe and evolution of scalar perturbations are studied for the quintessential scalar fields $Q$ with the classical Lagrangian satisfying the additional condition $w=const$ or $c^2_a=0$. Both…
The postulate that all massless elementary fields have conformal Weyl local scaling symmetry has remarkable consequences for both cosmology and elementary particle physics. Conformal symmetry couples scalar and gravitational fields.…
Scalar fields describe interesting phenomena such as Higgs bosons, dark matter and dark energy, and are found to be quite common in physical theories. These fields are susceptible to gravitational forces so that being massless is not enough…
We investigate whether interaction between massive neutrinos and quintessence scalar field is the origin of the late time accelerated expansion of the universe. We present cosmological perturbation theory in neutrinos probe interacting…
Non-linear gravitational clustering in a universe dominated by dark energy, modelled by a `quintessence' scalar field, and cold dark matter with space-time varying mass is studied. Models of this type, where the variable mass is induced by…
In the general context of scalar-tensor theories, we consider a model in which a scalar field coupled to the Ricci scalar in the gravitational sector of the Lagrangian, is also playing the role of an ``Extended Quintessence'' field,…
In this work we investigate the evolution of a Universe consisted of a scalar field, a dark matter field and non-interacting baryonic matter and radiation. The scalar field, which plays the role of dark energy, is non-minimally coupled to…
We show that the chameleon scalar field can drive the current phase of cosmic acceleration for a large class of scalar potentials that are also consistent with local tests of gravity. These provide explicit realizations of a quintessence…
Several detection strategies for wave-like dark matter make use of gradients in the dark matter field, e.g. searches for spin-dependent derivative interactions in CASPEr-wind or experiments looking for oscillating forces. These gradients…
Most parameterizations of the dark energy equation of state do not reflect realistic underlying physical models. Here, we develop a relatively simple description of dark energy based on the dynamics of a scalar field which is exact in the…
Our research focus on gravitational collapse of electrically charged scalar field in dilaton gravity and in the presence of phantom coupling. We examine dynamical behaviour of the scalar field coupled to Maxwell field when gravitational…
We demonstrate that massive fields, such as dark matter, can directly produce a cosmological evolution of the fundamental constants of Nature. We show that a scalar or pseudoscalar (axion-like) dark matter field $\phi$, which forms a…
The origin of galactic and extra-galactic magnetic fields is an unsolved problem in modern cosmology. A possible scenario comes from the idea of these fields emerged from a small field, a seed, which was produced in the early universe…
The background dynamical evolution of a universe filled with matter and a cosmological scalar field is analyzed employing dynamical system techniques. After the phenomenology of a canonical scalar field with exponential potential is…
The framework for considering the astronomical and cosmological observations in the context of scalar-tensor quintessence in which the quintessence field also accounts for a time dependence of the gravitational constant is developed. The…