Related papers: Dark energy based on exotic statistics
In the standard model of cosmology, the present evolution of the Universe is determined by the presence of two components of unknown nature. One of them is referenced as ``dark matter'' to justify the fact that it behaves cosmologically…
Recent measurements suggest our universe has a substantial dark energy component, which is usually interpreted in terms of a cosmological constant. Here we examine how much the form of this dark energy can be modified while still retaining…
We investigate several varying-mass dark-matter particle models in the framework of phantom cosmology. We examine whether there exist late-time cosmological solutions, corresponding to an accelerating universe and possessing dark energy and…
In this work we review some of the theoretical efforts and experimental evidences related to Dark matter and Dark energy problems in the universe. These dilemmas show us how incomplete our knowledge of gravity is, and how our concepts about…
It is shown that dark energy can be obtained from the interplay of the Higgs boson and the inflaton. A key element is the realization that electroweak symmetry breaking can trigger a second phase of rolling of the inflaton, which, when…
String theories suggest the existence of a plethora of axion-like fields with masses spread over a huge number of decades. Here we show that these ideas lend themselves to a model of quintessence with no super-Planckian field excursions and…
In this paper we review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating Universe. In particular we discuss the arguments for and recent progress made towards…
Observational evidence for the existence of dark energy is strong. Here we suggest a model which is based on a modified gravitational theory in 5D and interpret the 5th dimension as a manifestation of dark energy in the 4D observable…
Observations suggest that nearly seventy per cent of the energy density in the universe is unclustered and exerts negative pressure. Theoretical understanding of this component (`dark energy'), which is driving an accelerated expansion of…
Dark energy (i.e., a cosmological constant) leads, in the Newtonian approximation, to a repulsive force which grows linearly with distance and which can have astrophysical consequences. For example, the dark energy force overcomes the…
A huge amount of good quality astrophysical data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision…
A long-standing problem of theoretical physics is the exceptionally small value of the cosmological constant $\Lambda \sim 10^{-120}$ measured in natural Planckian units. Here we derive this tiny number from a toroidal string cosmology…
In the contemporary Cosmology, dark energy is modeled as a perfect fluid, having a very simple equation of state: pressure is proportional to dark energy density. As an alternative, I propose a more complex equation of state, with pressure…
We study physics concerning the cosmological constant problem in the framework of effective field theory and suggest that a dominant part of dark energy can originate from gravitational corrections of vacuum energy, under the assumption…
The physics community has adopted the principle that when new experimental data appears, physicists should first try to explain it based on existing science. Only if all such attempts fail can new exotic explanations be brought in. However,…
The acceleration of the expansion of the universe, ascribed to a dark energy, is one of the most intriguing discoveries in science. In addition to precise, systematics controlled data, clear, robust interpretation of the observations is…
It is argued that fluctuations of quantum fields in four-dimensional space do not give rise to dark energy, but are rather a negligible contribution to dark matter. By (relativistic) dark matter we mean that the relation between pressure…
The two apparently distinct phenomena of dark energy (or late-time cosmic acceleration) and quantum gravity dominate physics on extremely low, and extremely high energies, but do not seem to have any apparent empirical connection.…
The concept of an all pervading Aether is age old, and contrary to popular belief, it survived the twentieth century too though with different nuances. Using this concept of a background Quantum Vacuum, the author in 1997 proposed a…
Various astronomical observations point towards the evidence for dark energy. One of the most mysterious problem is the coincidence problem: why dark energy becomes dominant only recently. We present a scenario based on extended…