‘Dark Energy is Mysterious’ it realy exits or it is simply coined ?

In the late 1990s astronomers made a revolutionary discovery: the expansion of our Universe is accelerating. One of today's greatest scientific challenges is to understand what is causing this acceleration. Lacking any deep understanding of this mysterious force, and without the ability to probe it directly with existing technology, physicists coined the generic term "dark energy" to describe it. Whatever dark energy actually is, detailed measurements from independent techniques reveal that it comprises a whopping 74% of our Universe's total mass-energy.[…]

Recent Studies on the Dark Energy:

• Earth Not Center Of The Universe, Surrounded By 'Dark Energy': Earth's location in the universe is utterly unremarkable, despite recent theories that propose toppling a foundation of modern cosmology, according to a team of University of British Columbia researchers.[1]
• Dark Energy May Be Vacuum: Researchers at the University of Copenhagen's Dark Cosmology Centre at the Niels Bohr Institute have brought us one step closer to understanding what the universe is made of. The new data shows that vacuum energy is the most likely cause and the expansion history of the universe can be explained by simply adding this constant background of acceleration into the normal theory of gravity.[2]
• Einstein's Biggest Blunder? Dark Energy May Be Consistent With Cosmological Constant: Einstein's self-proclaimed "biggest blunder" -- his postulation of a cosmological constant (a force that opposes gravity and keeps the universe from collapsing) -- may not be such a blunder after all, according to the research of an international team of scientists.[3]
• Einstein's Dark Energy Accelerates The Universe: The genius of Albert Einstein, who added a "cosmological constant" to his equation for the expansion of the universe but later retracted it, may be vindicated by new research published today in the journal Astronomy and Astrophysics.[4]
• Einstein's 'Biggest Blunder'? New Supernovae Study Offers Tantalyzing Clues About Dark Energy: The genius of Albert Einstein, who added a "cosmological constant" to his equation for the expansion of the universe but later retracted it, may be vindicated by new research. The enigmatic dark energy that drives the accelerating expansion of the universe behaves just like Einstein's famed cosmological constant, according to the Supernova Legacy Survey (SNLS). The observations reveal that the dark energy behaves like Einstein's cosmological constant to a precision of 10 per cent.[5]
• New Clues About The Nature Of Dark Energy: Einstein May Have Been Right After All: A strange form of energy called "dark energy" is looking a little more like the repulsive force Einstein theorized in an attempt to balance the universe against its own gravity. Even if Einstein turns out to be wrong, the universe's dark energy probably won't destroy the universe any sooner than about 30 billion years from now, say Hubble researchers.[6]