A Mechanics-Based Dark Energy Model in a 4+1-Dimensional Medium

In this paper, a mechanistic model for dark energy is proposed by introducing a four-dimensional spatial medium, with time as an independent variable. The electromagnetic force field and resulting stress field and gravitational stress field are assumed to be present in the medium. The mechanical model of the medium and the interaction mechanism between medium and matter are modeled to satisfy the field behavior described by quantum electrodynamics and space-time geometry described by relativity theory. To define the mechanical properties of the medium, the eigen states used to describe an electromagnetic field are assumed to have a physical basis, with mass and stiffness associated with the eigen states. The four-dimensional medium is assumed to be elastic and orthotropic, with isotropic properties along space, and a smaller stiffness along the spatial axis corresponding to time axis in space-time. Mechanical models using the Formula: see text-dimensional medium is then developed to explain Lorentz transformation, gravitation and behavior in electromagnetic fields. A local realistic model for spin of electrons in a atom is then discussed using the proposed framework. The mechanistic model for large and small scale interactions is utilized to propose release of strain energy in medium as the mechanism to explain dark energy. At big bang the medium is assumed to be in a state of gravitational stress from a massive black hole, and the transient state due to the release of strain energy after big bang is considered as the source of dark energy. The features of Lambda Cold Dark Matter (Formula: see textCDM) model and mechanism for big bang are then explained using this definition of dark energy.