The Interacting Holographic Dark Energy And The Local Influence Of Quintessence

Since 1998 the observation of the type la Supernovae has shown that the universe is undergoing an era of accelerated expansion. Data from other observations such as Wilkinson Microwave Anisotropy Probe, Cosmic Microwave Background Radiation, Sloan Digital Sky Survey and Large Scale Structure also give support to the phenomenon. These data reveal that the present universe is dominated by an exotic component, dubbed dark energy, which has negative pressure to accelerate the expansion of the universe. Therefore, in order to explain this bizarre phenomenon, various models of dark energy have been put forward, ranging from a cosmological constant to the scalar field theories of dark energy and modified gravity theories as well. The cosmological constant, which is simplest, corresponds to the vacuum energy with constant energy and pressure while the scalar fields a time dependent equation of state parameter. The modified theories change the geometric structures of space-time. Recently, another model inspired by the holographic principle has been put forward to explain the dark energy. The holographic principle, enlightened by the quantum properties of black holes, is one of the most important results in recent investigations of quantum gravity. In essence the dark energy problem should be an issue of quantum gravity, so the holographic dark energy model may have some significant characters of underlying theories of dark energy.Based on investigations done before, the general holographic dark energy model is natu-rally extended to the form with interaction between dark energy and dark matter, expecting to enrich the theoretical studies of series of holographic dark energy models. The analytic forms for the cosmic parameters are obtained under the specific boundary conditions. The various behaviors concerning the cosmic expansion depend on the introduced numerical pa-rameters which are also constrained. The general interacting model not only solves problems like fine-tuning, cosmic correspondence and causality, but also inherits the features of pre-vious models of holographic dark energy, keeping the consistency of the theory. Moreover, when the effective equation of state of dark energy is considered, the unfavorable big rip sin-gularity can be eliminated. Nevertheless, so far dark energy models have grown in number, so an approach is claimed to differentiate between them. As is well known, the statefinder is a sensitive and robust geometrical diagnostic of dark energy. The statefinder diagnostic is applied to the general holographic dark energy model without and with interaction. It is shown that the behavior of the interacting model is more like other holographic dark energy models, which means that the general holographic dark energy model with interaction is favored.On the other hand, taking dark energy for the presumed cosmological component is also used, combined with the Einstein field equations, to deal with some local gravitational issues, such as the relevant features of black holes. With the metric for Schwarzschild space surrounded by the quintessential matter given by Kiselev, the trajectories and the orbital precession of test bodies on the motion of a binary system are studied to detect the influence of quintessence in the local gravitational field. Similar to the classic tests of Einstein's general relativity, the results gotten here can be used to explore whether dark energy exists or not along with the improvement upon observational techniques in astronomy.