RESUMO
The inherently unstable nature of domain walls makes their detection in laboratory experiments extremely challenging. We propose a method to stabilize domain walls inside a cavity. The method requires domain walls coupled to matter, a condition that is fulfilled by the symmetron model. We suggest two ways in which the walls could be detected once stabilized: studying the trajectories of ultracold neutrons either via the deflection angle of a neutron beam induced by the attraction towards the wall or through the time difference of these particles passing through the wall. We give realistic estimates for these effects and expect that they should be detectable experimentally.
RESUMO
Several extensions of general relativity and high energy physics include scalar fields as extra degrees of freedom. In the search for predictions in the nonlinear regime of cosmological evolution, the community makes use of numerical simulations in which the quasistatic limit is assumed when solving the equation of motion of the scalar field. In this Letter, we propose a method to solve the full equations of motion for scalar degrees of freedom coupled to matter. We run cosmological simulations which track the full time and space evolution of the scalar field, and find striking differences with respect to the commonly used quasistatic approximation. This novel procedure reveals new physical properties of the scalar field and uncovers concealed astrophysical phenomena which were hidden in the old approach.
RESUMO
Scalar fields are crucial components in high energy physics and extensions of general relativity. The fact that 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 observations of the ellipticity of galaxy clusters can discriminate between models with and without scalar fields and even between different screening mechanisms. Using current x-ray observations we put novel constraints on the different models.