Dark Energy: From Einstein’s Biggest Blunder to the Holographic Universe
Not Available / Digital Item
Dark Energy: From Einstein’s Biggest Blunder to the Holographic Universe
Understanding the mysterious nature and origin of dark energy is one of the most important quests in modern cosmology and fundamental physics. The 2011 Nobel Prize in Physics was awarded to Saul Perlmutter, Brian P. Schmidt and Adam G. Riess for their significant discovery of cosmic acceleration due to dark energy. However, nobody knows what dark energy actually is.
This book gives a clear and concise introduction to the main dark energy models, including the cosmological constant, which Einstein called the biggest blunder of his lifetime. In particular, it analyzes in detail the possible holographic origin of dark energy. Based on a deep analysis of existing ideas, the book also proposes an intriguing conjecture on the origin of dark energy, according to which the dark energy originates from the quantum fluctuations of spacetime limited by the discretized event horizon of the universe. This book will be of value to all those with an interest in cosmology and fundamental physics.
Book Excerpt:
The most recent results have already brought surprises: the universe’s expansion is apparently accelerating rather than decelerating as expected due to gravity. These measurements indicate the presence of a new, exotic energy component that can cause acceleration. These are fundamental questions: How is field theory manifest today in the form of dark energy? Will the acceleration continue without end in a new inflationary epoch or does the dark energy fade and gravity decelerate the expansion? --- Eric Linder and Saul Perlmutter, Lawrence Berkeley National Laboratory
Our best attempts at a fundamental theory suggest the presence of a cosmological constant that is many (perhaps as many as 120) orders of magnitude greater than the upper bound set by astronomical observations. Now that a dark energy has apparently been found, the problem is even harder. It is difficult for physicists to attack this problem without knowing just what it is that needs to be explained - a cosmological constant or a dark energy that changes with time as the universe evolves - and for this they must rely on new observations by astronomers. --- Steven Weinberg, University of Texas at Austin
The density of “empty†space, as measured by gravity, is many orders of magnitude smaller than our current understanding of fundamental physics seems to suggest. In my opinion, this disparity is the biggest and most profound gap in our current understanding of the physical world. It is not completely fanciful to imagine that this problem will play, in twenty-first century physics, a role analogous to that played by the problem of black-body radiation in twentieth century physics. It might require inventing entirely new ideas, and abandoning old ones we thought to be well-established. --- Frank Wilczek, Massachusetts Institute of Technology
One of the most perplexing issues in physics is why the energy of the vacuum is so incredibly small. Observations of an apparently nonzero vacuum energy have come as a great surprise. For the future development of fundamental physics, it is vitally important to know if the cosmological “constant,†as inferred from these observations, is truly constant, or if the observations point to some form of cosmic evolution (sometimes called “quintessenceâ€). Precise exploration of these exciting questions is likely to have a major impact in physics as well as in astronomy. --- Edward Witten, Institute for Advanced Study
Established theories of particle physics make contributions to the cosmological vacuum energy that are many orders of magnitude greater than its possible value. No convincing mechanism for cancelling the vacuum energy has been formed in string theory. Clarifications of the magnitude of the vacuum energy and its equation of state are of crucial importance for fundamental physics, as well as for cosmology. --- John Ellis, CERN