Related papers: Towards a UV Completion for Chameleon Scalar Theor…
Light scalar fields play a variety of roles in modern physics, especially in cosmology and modified theories of gravity. For this reason, there is a zoo of experiments actively trying to find evidence for many scalar field models that have…
Current acceleration of the cosmic expansion leads to coincidence as well as fine-tuning issues in the framework of general relativity. Dynamical scalar fields have been introduced in response of these problems, some of them invoking…
We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential…
Stringent Swampland conjectures aimed at effective theories containing massive abelian vectors have recently been proposed (arXiv:1808.09966), with striking phenomenological implications. In this article, we show how effective theories that…
Models where the accelerated expansion of our Universe is caused by a quintessence scalar field are reviewed. In the framework of high energy physics, the physical nature of this field is discussed and its interaction with ordinary matter…
In general, modified gravity theories are modifications or extensions of Einstein's general relativity. Some of them give rise to additional scalar degrees of freedom in Nature. If these scalar fields exist and are light enough, they should…
Ultralight scalar dark matter may couple to the Standard Model through dimension-five operators that contain the field-strength tensors of the gauge interactions. Recent progress in nuclear clocks is projected to increase the sensitivity to…
Chameleon, environmentally dependent dilaton, and symmetron gravity are three models of modified gravity in which the effects of the additional scalar degree of freedom are screened in dense environments. They have been extensively studied…
In chameleon dark energy models, local gravity constraints tend to rule out parameters in which observable cosmological signatures can be found. We study viable chameleon potentials consistent with a number of recent observational and…
We discuss the scalar mode of gravitational waves emerging in the context of $F(R)$ gravity by taking into account the chameleon mechanism. Assuming a toy model with a specific matter distribution to reproduce the environment of detection…
In conventional approach to the chameleon mechanism, by assuming a static and spherically symmetric solutions in which matter density and chameleon field are given by $\rho=\rho(r)$ and $\phi=\phi(r)$, it has been shown that mass of…
It has been suggested that a certain class of UV-incomplete quantum field theories can avoid unitarity violation above the cut-off energy scale by forming classical configurations at a length scale much larger than the cut-off length. This…
In this paper, we examine the cosmological viability of a light mass galileon field consistent with local gravity constraints. The minimal, L_3=\Box\phi(\partial_\mu \phi)^2, massless galileon field requires an additional term in order to…
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…
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…
A scalar field is a favorite candidate for the particle responsible for dark energy. However, few theoretical means exist that can simultaneously explain the observed acceleration of the Universe and evade tests of gravity. The chameleon…
We compute bounds from atomic spectroscopy on chameleon fields that couple to the photon. Chameleons are a wide class of scalar field models that generically lead to screened fifth forces and a host of novel phenomenologies, particularly…
We investigate laboratory tests of dark energy theories which modify gravity in a way generalising the inverse power law chameleon models. We make use of the tomographic description of such theories which captures $f(R)$ models in the large…
Most theories that predict time and/or space variation of fundamental constants also predict violations of the Weak Equivalence Principle. In 2004 Khoury and Weltman proposed the so called chameleon field arguing that it could help avoiding…
We present a framework for embedding scalar-tensor models of screened modifed gravity such as chameleons, symmetrons and environmental dilatons into global supersymmetry. This achieved by secluding the dark sector from both the observable…