Unifying phantom inflation with late-time acceleration: scalar phantom-non-phantom transition model and generalized holographic dark energy

摘要

The unifying approach to early-time and late-time universe based on phantomcosmology is proposed. We consider gravity-scalar system which contains usualpotential and scalar coupling function in front of kinetic term. As a result,the possibility of phantom-non-phantom transition appears in such a way thatuniverse could have effectively phantom equation of state at early time as wellas at late time. In fact, the oscillating universe may have several phantom andnon-phantom phases. As a second model we suggest generalized holographic darkenergy where infrared cutoff is identified with combination of FRW parameters:Hubble constant, particle and future horizons, cosmological constant anduniverse life-time (if finite). Depending on the specific choice of the modelthe number of interesting effects occur: the possibility to solve thecoincidence problem, crossing of phantom divide and unification of early-timeinflationary and late-time accelerating phantom universe. The bound forholographic entropy which decreases in phantom era is also discussed.