Related papers: Constraining chameleon field theories using the Ga…
This article investigates the profile of the scalar field of a scalar-tensor theory subject to the chameleon mechanism in the context of gravity space missions like the MICROSCOPE experiment. It analyses the experimental situations for…
Laboratory experiments can shed light on theories of new physics introduced in order to explain cosmological mysteries, including the nature of dark energy and dark matter. In this article I will focus on one particular example of this, the…
We model the chameleon effect on cosmological statistics for the modified gravity f(R) model of cosmic acceleration. The chameleon effect, required to make the model compatible with local tests of gravity, reduces force enhancement as a…
In this article we discuss some aspects of solar physics from the standpoint of the so-called chameleon fields (i.e. quantum fields, typically scalar, where the mass is an increasing function of the matter density of the environment).…
We investigate the gas density, temperature, and pressure profiles in a dark matter halo under the influence of the chameleon force. We solve the hydrostatic equilibrium equation for the gas coupled with the chameleon field in an analytic…
As a result of non-linear self-interactions, in chameleon theories where the field couples to matter much more strongly than gravity does, the fifth force between two bodies with thin-shell is independent of their coupling to the field. As…
We investigate the effects of chameleon scalar field to the effective density and pressure of a dark matter halo. The pressure is generated from the chameleonic fifth force on the matter. We demonstrate that the thick-shell non-singular…
There is a deep connection between cosmology -- the science of the infinitely large --and particle physics -- the science of the infinitely small. This connection is particularly manifest in neutron particle physics. Basic properties of the…
The consideration is presented of possible neutron Lloyd's mirror interferometer experiment to search for strongly coupled chameleon fields. The chameleon scalar fields were proposed to explain the early and late time acceleration of…
Recent results from direct detection experiments such as LUX, PANDAX-II and XENON100 have imposed severe constraints on the multi-GeV mass window in various dark matter (DM) models. However, many of these experiments are not sensitive to…
The chameleon mechanism is a way to give an effective mass to a light scalar field via field self-interaction and interaction with matter. We study this mechanism in models in which the couplings are field dependent and find that the…
We use previously obtained experimental results by neutron interferometry to effectively constrain the parameter space of several prominent dark energy models. This investigation encompasses the environment-dependent dilaton field, a…
The indirect detection of dark matter particles with mass below the GeV scale has recently received significant attention. Future space-borne gamma-ray telescopes, including All-Sky-ASTROGAM, AMEGO, and GECCO, will probe the MeV gamma-ray…
We investigate the cosmological dynamics of the recently proposed extended chameleon models at both background and linear perturbation levels. Dynamical systems techniques are employed to fully characterize the evolution of the universe at…
In the chameleon mechanism, a field (typically scalar) has a mass that depends on the matter density of the environment: the larger is the matter density, the larger is the mass of the chameleon. We briefly review some aspects of…
It was recently argued that the observed PVLAS anomaly can be explained by chameleon field theories in which large deviations from Newton's law can be avoided. Here we present the predictions for the dichroism and the birefringence induced…
Dark matter is poorly constrained by direct detection experiments at masses below 1 MeV. This is an important target for the next generation of experiments, and several methods have been proposed to probe this mass range. One class of such…
We tested a fifth force using cold atom experiments. The accelerated expansion of the universe implies the possibility of the presence of a scalar field throughout the universe driving the acceleration. This field would result in a…
The physics of the "dark energy" that drives the current cosmological acceleration remains mysterious, and the dark sector may involve new light dynamical fields. If these light scalars couple to matter, a screening mechanism must prevent…
We show that a direct coupling between a chameleon-like scalar field and photons can give rise to a modified Sunyaev-Zel'dovich (SZ) effect in the Cosmic Microwave Background (CMB). The coupling induces a mixing between chameleon particles…