Related papers: Fifth-Force Screening around Extremely Compact Sou…
Axion-mediated forces are enhanced by the presence of CP-violating axion couplings, which are however tightly constrained by electric dipole moment (EDM) searches. We discuss the underlying hypotheses behind different sources of CP…
Chameleon and similar (symmetron and dilation) theories of gravity can exhibit new and interesting features on cosmological scales whilst screening the modifications on small scales thereby satisfying solar system tests of general…
This Essay explores consequences of a dark non-linear electromagnetic sector in a Universe with a net dark charge for matter. The cosmological dynamics can be described by a Lema\^itre model and understood thanks to a screening mechanism…
Spin-dependent fifth-forces are associated with particles beyond the standard model. In particular, light pseudo-scalar bosons mediate long-range forces, allowing mass to interact with spins. The search of these interactions can be…
In chameleon field theories a scalar field can couple to matter with gravitational strength and still evade local gravity constraints due to a combination of self-interactions and the couplings to matter. Originally, these theories were…
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…
We consider a long range scalar force that mainly couples to dark matter and unstable Standard Model states, like the muon, with tiny strength. Probing this type of force would present a challenge to observations. We point out that the…
We report results from the GammeV Chameleon Afterglow Search---a search for chameleon particles created via photon/chameleon oscillations within a magnetic field. This experiment is sensitive to a wide class of chameleon power-law models…
We show that the current bounds on the time variation of the Newton constant G can put severe constraints on many interesting scalar-tensor theories which possess a shift symmetry and a nonminimal matter-scalar coupling. This includes, in…
Chameleon scalar field is a new model, which introduced to provide a mechanism for exhibiting accelerating universe. Chameleon field has several interesting aspects, such as field dependence on the local matter density. For this model we…
We study observational bounds in a class of scalar-tensor gravity theories recently proposed. Either an upper or lower bound on a conformal factor in these theories is derived from null observation in composition dependent fifth force…
Low-energy effective field theories containing a light scalar field are used extensively in cosmology, but often there is a tension between embedding such theories in a healthy UV completion and achieving a phenomenologically viable…
Models of modified gravity, whereby local tests of gravity are evaded thanks to a screening mechanism of the chameleon or Damour-Polyakov types, lead to a spatial variation of the particle masses and the fine structure constant. This is…
We investigate scalar-tensor theories where matter couples to the scalar field via a kinetically dependent conformal coupling. These models can be seen as the low-energy description of invariant field theories under a global Abelian…
The search for CP violating forces between nucleons in the so-called axion window of force ranges lam between 2x10^-5 m and 0.02 m is interesting because only little experimental information is available there. Axion-like particles would…
We study models in which a light scalar dark energy particle couples to the gauge fields of the electroweak force, the photon, Z and W bosons. Our analysis applies to a large class of interacting dark energy models, including those in which…
Chameleon gravity is an example of a model that gives rise to interesting phenomenology on cosmological scales while simultaneously possessing a screening mechanism, allowing it to avoid solar system constraints. Such models result in…
We investigate an Early Coupled Quintessence model where a light scalar mediates a fifth force stronger than gravity among dark matter particles and leads to the growth of perturbations prior to matter-radiation equality. Using cosmological…
This work provides the first comparison of the symmetron and dilaton fields in white dwarfs. We show how these screening mechanisms behave inside {such stars} and their impact on stellar properties. Employing a custom-developed shooting…
The environment-dependent dilaton field is a well-motivated candidate for dark energy and naturally arises in the strong coupling limit of string theory. In this article, we present the very first experimental constraints on the parameters…