منابع مشابه
Gravitational energy and cosmic acceleration
Cosmic acceleration is explained quantitatively, as an apparent effect due to gravitational energy differences that arise in the decoupling of bound systems from the global expansion of the universe. “Dark energy” is a misidentification of those aspects of gravitational energy which by virtue of the equivalence principle cannot be localised, namely gradients in the energy due to the expansion o...
متن کاملCosmic Acceleration, Dark Energy, and Fundamental Physics
A web of interlocking observations has established that the expansion of the Universe is speeding up and not slowing, revealing the presence of some form of repulsive gravity. Within the context of general relativity the cause of cosmic acceleration is a highly elastic (p " #!), very smooth form of energy called ‘‘dark energy’’ accounting for about 75% of the Universe. The ‘‘simplest’’ explanat...
متن کاملHolographic dark energy and late cosmic acceleration
It has been persuasively argued that the number of the effective degrees of freedom of a macroscopic system is proportional to its area rather than to its volume. This entails interesting consequences for cosmology. Here we present a model based on this “holographic principle” that accounts for the present stage of accelerated expansion of the Universe and significantly alleviates the coinciden...
متن کاملLectures on Dark Energy and Cosmic Acceleration
The discovery ten years ago that the expansion of the Universe is accelerating put in place the present cosmological model, in which the Universe is composed of 4% baryons, 20% dark matter, and 76% dark energy. Yet the underlying cause of cosmic acceleration remains a mystery: it could arise from the repulsive gravity of dark energy – for example, the quantum energy of the vacuum – or it may si...
متن کاملHolographic Dark Energy and Present Cosmic Acceleration
We review the notion of holographic dark energy and assess its significance in the light of the well documented cosmic acceleration at the present time. We next propose a model of holographic dark energy in which the infrared cutoff is set by the Hubble scale. The model accounts for the aforesaid acceleration and, by construction, is free of the cosmic coincidence problem.
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ژورنال
عنوان ژورنال: Physical Review D
سال: 2007
ISSN: 1550-7998,1550-2368
DOI: 10.1103/physrevd.75.083523