Related papers: Quantum corrections to symmetron fifth-force profi…
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…
Screening mechanisms allow light scalar fields to dynamically avoid the constraints that come from our lack of observation of a long-range fifth force. Galactic scale tests are of particular interest when the light scalar is introduced to…
Many non-linear scalar field theories possess a screening mechanism that can suppress any associated fifth force in dense environments. As a result, these theories can evade local experimental tests of new forces. Chameleon-like screening,…
Scalar-tensor theories with screening mechanisms come with non-linearities that make it difficult to study setups of complex geometry without resorting to numerical simulations. In this article, we use the $\textit{femtoscope}$ code that we…
The evidence for the observation of the Higgs spin-0-boson as a manifestation of a scalar field provides the missing corner stone for the standard model of particles (SM). However, the SM fails to explain the non-visible but gravitationally…
A light scalar field framework of dark energy, sometimes referred to as quintessence, introduces a fifth force between normal matter objects. Screening mechanisms, such as the chameleon model, allow the scalar field to be almost massless on…
Light scalars generically mediate a fifth force incompatible with local tests of gravity unless their couplings are parametrically suppressed or screening mechanisms are introduced. We demonstrate that such suppression can arise from…
Chameleon scalar fields are dark energy candidates which suppress fifth forces in high density regions of the universe by becoming massive. We consider chameleon models as effective field theories and estimate quantum corrections to their…
Scalar field theories that possess a Vainshtein mechanism are able to dynamically suppress the associated fifth forces in the presence of massive sources through derivative non-linearities. The resulting equations of motion for the scalar…
The symmetron scalar field is a matter-coupled dark energy candidate which effectively decouples from matter in high-density regions through a symmetry restoration. We consider a previously unexplored regime, in which the vacuum mass $\mu…
In Einstein's General Relativity (GR), the gravitational interactions are described by the spacetime curvature. Recently, other alternative geometric formulations and representations of GR have emerged in which the gravitational…
We investigate linear and non-linear dynamics of spherically symmetric perturbations on a static configuration in scalar-tensor theories focusing on the chameleon screening mechanism. We particularly address two questions: how much the…
The discovery of cosmic acceleration motivated extensive studies of dynamical dark energy and modified gravity models. Of particular interest are the scalar-tensor theories, with a scalar field dark energy non-minimally coupled to matter.…
We study a screening mechanism in the context of scalar-vector-tensor (SVT) theories. This screening mechanism is based on both the derivative self-interactions of the vector field and the interactions of the scalar field with the vector…
Scalar fields, strongly coupled to matter, can be present in nature and still be invisible to local experiments if they are subject to a screening mechanism. The symmetron is one such mechanism which relies on restoration of a spontaneously…
Scalar-tensor theories are frequently only consistent with fifth force constraints in the presence of a screening mechanism, namely in order to suppress an otherwise unacceptably large coupling between the scalar and ordinary matter. Here…
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…
Symmetron field is one of the promising candidates of dark energy scalar fields. In all viable candidate field theories, a screening mechanism is implemented to be consistent with existing tests of general relativity. The screening effect…
Despite the overwhelming evidence for the existence of dark energy and dark matter, their underlying fundamental physics remains unknown. This review article explores the tantalizing possibility that the dark sector includes new light…
New fifth forces have not yet been detected in the laboratory or in the solar system, hence it is typically difficult to introduce new light scalar fields that would mediate such forces. In recent years it has been shown that a number of…