Related papers: Structure Formation in the Symmetron Model
We study the formation of structure in the Universe assuming that dark matter can be described by a scalar field $\tilde{\Phi}$ with a potential $V(\Phi)=-\mathfrak{m}^{2}\tilde{\Phi}^{2}/2+\lambda\tilde{\Phi}^4/4$. We derive the evolution…
We offer predictions of symmetron modified gravity in the neighborhood of realistic dark matter halos. The predictions for the fifth force are obtained by solving the nonlinear symmetron equation of motion in the spherical NFW…
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…
Scalar fields are crucial components in high energy physics and extensions of General Relativity. The fact they are not observed in the solar system may be due to a mechanism which screens their presence in high dense regions. We show how…
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…
Scalar fields coupled to gravity through the Ricci scalar have been considered both as dark matter candidates and as a possible modified gravity explanation for galactic dynamics. It has recently been demonstrated that the dynamics of…
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…
We investigate the validity of screening mechanism of the fifth force for chameleon field in highly inhomogeneous density profile. For simplicity, we consider a static and spherically symmetric system which is composed of concentric…
Chameleon scalar fields can screen their associated fifth forces from detection by changing their mass with the local density. These models are an archetypal example of a screening mechanism, and have become an important target for both…
The mass of a scalar field mediating a fifth force is tightly constrained by experiments. We show, however, that adding a quartic self-interaction for such a scalar makes most tests much less constraining: the non-linear equation of motion…
Motivated in part by string theory, we consider a modification of the LambdaCDM cosmological model in which the dark matter has a long-range scalar force screened by light particles. Scalar forces can have interesting effects on structure…
When augmenting our cosmological models or gravitational theories with an additional light scalar field, any coupling between matter and this scalar can affect the orbital motion of binary systems. Ordinarily, the new force mediated by the…
Nonlinear scalar-tensor theories of gravity have been considered as candidates for dark matter and dark energy. Often, they possess screening mechanisms, which allow the fifth force mediated by the additional scalar degree(s) of freedom to…
The symmetron model is a scalar-tensor theory of gravity with a screening mechanism that suppresses the effect of the symmetron field at high densities characteristic of the solar system and laboratory scales but allows it to act with…
The symmetron, one of the light scalar fields introduced by dark energy theories, is thought to modify the gravitational force when it couples to matter. However, detecting the symmetron field is challenging due to its screening behavior in…
This article investigates the properties of a scalar fifth force that arises in a scalar tensor-theory with a chameleon screening mechanism in the context of gravity space missions like the MICROSCOPE experiment. In such an experiment, the…
Screening mechanisms are a natural method for suppressing long-range forces in scalar-tensor theories as they link the local background density to their strength. Focusing on Brans-Dicke theories, those including a non-minimal coupling…
We propose a novel mechanism which explains cored dark matter density profile in recently observed dark matter rich dwarf spheroidal galaxies. In our scenario, dark matter particle mass decreases gradually as function of distance towards…
The symmetron field has an environment (density) dependent behavior which is a common feature of the models with the screening mechanism and results in a rich phenomenology. This model can produce domain walls between regions with different…
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…