Written for the educated non-scientist and scientist alike, it spans a variety of scientific disciplines, from observational astronomy to particle physics. Concepts that the reader will encounter along the way are at the cutting edge of scientific research. However the themes are explained in such a way that no prior understanding of science beyond a high school education is necessary.
This volume is the latest in a prominent biannual series of scientific meetings on the exciting research topics of dark matter and, more recently, of dark energy. It contains a state-of-the-art update on detection efforts by experimental groups around the world trying to pin down exotic new forms of matter under the names of axions, neutralinos, wimps, primordial black holes, q balls, sterile neutrinos, as well as a tantalizing new form of dark energy component called phantom energy and quintessence. The book is self-contained as it also includes general reviews on recent cosmological observations ? supernovae measurements, cosmic matter distribution surveys and cosmic radiation anisotropies ? introducing even the uninitiated reader to this fascinating frontier of research.
In this classic text, a Nobel Prize-winning astrophysicist presents the theory of stellar dynamics as a branch of classical dynamics--a discipline in the same general category as celestial mechanics. His method offers the advantages of clarifying the theory's fundamental issues and defining its underlying motivations. S. Chandrasekhar investigates two areas. The first concerns problems in which the time of relaxation of a stellar system is central. His method consists of analyzing the effects of stellar encounters in terms of the two-body problem of classical dynamics and applying this theory to the dynamics of star clusters. The second area investigates problems centering around Liouville's theorem and the solutions of the equation of continuity; here, the author discusses the dynamic implications of the existence of a field of differential motions, which appears to be the most striking kinematic feature of the galaxy and the extragalactic systems. This edition includes two papers by the author that were published after Principles of Stellar Dynamics and that have been studied and quoted extensively: "New Methods in Stellar Dynamics" (originally published in the Annals of the New York Academy of Sciences) and "Dynamical Friction" (originally published in The Astrophysical Journal).
The twentieth century was astonishing in all regards, shaking the foundations of practically every aspect of human life and thought, physics not least of all. Beginning with the publication of Albert Einstein's theory of relativity, through the wild revolution of quantum mechanics, and up until the physics of the modern day (including the astonishing revelation, in 1998, that the Universe is not only expanding, but doing so at an ever-quickening pace), much of what physicists have seen in our Universe suggests that much of our Universe is unseen—that we live in a dark cosmos. Everyone knows that there are things no one can see—the air you're breathing, for example, or, to be more exotic, a black hole. But what everyone does not know is that what we can see—a book, a cat, or our planet—makes up only 5 percent of the Universe. The rest—fully 95 percent—is totally invisible to us; its presence discernible only by the weak effects it has on visible matter around it. This invisible stuff comes in two varieties—dark matter and dark energy. One holds the Universe together, while the other tears it apart. What these forces really are has been a mystery for as long as anyone has suspected they were there, but the latest discoveries of experimental physics have brought us closer to that knowledge. Particle physicist Dan Hooper takes his readers, with wit, grace, and a keen knack for explaining the toughest ideas science has to offer, on a quest few would have ever expected: to discover what makes up our dark cosmos.
Searching for Dark Matter with Cosmic Gamma Rays summarizes the evidence for dark matter and what we can learn about its particle nature using cosmic gamma rays. It has almost been 100 years since Fritz Zwicky first detected hints that most of the matter in the Universe that doesn't directly emit or reflect light. Since then, the observational evidence for dark matter has continued to grow. Dark matter may be a new kind of particle that is governed by physics beyond our Standard Model of particle physics. In many models, dark matter annihilation or decay produces gamma rays. There are a variety of instruments observing the gamma-ray sky from tens of MeV to hundreds of TeV. Some make deep, focused observations of small regions, while others provide coverage of the entire sky. Each experiment offers complementary sensitivity to dark matter searches in a variety of target sizes, locations, and dark matter mass scales. We review results from recent gamma-ray experiments including anomalies some have attributed to dark matter. We also discuss how our gamma-ray observations complement other dark matter searches and the prospects for future experiments.
