The growth of cosmology into a precision science represents one of the most remarkable stories of the past century. Much has been written chronicling this development, but rarely has any of it focused on the most critical element of this work-the cosmic spacetime itself. Addressing this lacuna is the principal focus of this book, documenting the growing body of evidence compelling us-not only to use this famous solution to Einstein's equations in order to refine the current paradigm, but-to probe its foundation at a much deeper level. Its excursion from the smallest to largest possible scales insightfully reveals an emerging link between the Universe we behold and the established tenets of our most fundamental physical theories. Key Features: Uncovers the critical link between the Local Flatness Theorem in general relativity and the symmetries informing the spacetime's metric coefficients Develops a physical explanation for some of the most unpalatable coincidences in cosmology Provides a sober assessment of the horizon problems precluding our full understanding of the early Universe Reveals a possible explanation for the origin of rest-mass energy in Einstein's theory In spite of its technical layout, this book does not shy away from introducing the principal players who have made the most enduring contributions to this field. Anyone with a graduate level foundation in physics and astronomy will be able to easily follow its contents.

The growth of cosmology into a precision science represents one of the most remarkable stories of the past century. Much has been written chronicling this development, but rarely has any of it focused on the most critical element of this work-the cosmic spacetime itself. Addressing this lacuna is the principal focus of this book, documenting the growing body of evidence compelling us-not only to use this famous solution to Einstein's equations in order to refine the current paradigm, but-to probe its foundation at a much deeper level. Its excursion from the smallest to largest possible scales insightfully reveals an emerging link between the Universe we behold and the established tenets of our most fundamental physical theories. Key Features: Uncovers the critical link between the Local Flatness Theorem in general relativity and the symmetries informing the spacetime's metric coefficients Develops a physical explanation for some of the most unpalatable coincidences in cosmology Provides a sober assessment of the horizon problems precluding our full understanding of the early Universe Reveals a possible explanation for the origin of rest-mass energy in Einstein's theory In spite of its technical layout, this book does not shy away from introducing the principal players who have made the most enduring contributions to this field. Anyone with a graduate level foundation in physics and astronomy will be able to easily follow its contents.

Here, one of the world's leading astrophysicists provides the first comprehensive and logically structured overview of the many ideas and discoveries pertaining to the supermassive black hole at the galactic center known as Sagittarius A*. By far the closest galactic nucleus in the universe, Sagittarius A* alone can provide us with a realistic expectation of learning about the physics of strong gravitational fields, and the impact of such fields on the behavior of matter and radiation under severe physical conditions. Its proximity may even provide the opportunity to directly test one of general relativity's most enigmatic predictions--the existence of closed pockets of space-time hidden behind an event horizon.

The plethora of research on Sagittarius A* since its discovery in 1974 has long seemed an interwoven pattern of loose threads. No one has successfully synthesized this growing body of work into a manageable, coherent book both for professional researchers and for students taking courses focusing on black holes and galactic nuclei--until now. With Fulvio Melia's "The Galactic Supermassive Black Hole," readers finally have at their disposal a one-volume crucible of essential ideas, logically streamlined but with thorough references for those wishing to explore the various topics in greater depth.

Could Einstein have possibly anticipated directly testing the most captivating prediction of general relativity, that there exist isolated pockets of spacetime shielded completely from our own? Now, almost a century after that theory emerged, one of the world's leading astrophysicists presents a wealth of recent evidence that just such an entity, with a mass of about three million suns, is indeed lurking at the center of our galaxy, the Milky Way--in the form of a supermassive ''black hole''

With this superbly illustrated, elegantly written, nontechnical account of the most enigmatic astronomical object yet observed, Fulvio Melia captures all the excitement of the growing realization that we are on the verge of actually seeing this exotic object within the next few years.

Melia traces our intellectual pilgrimage to the ''brooding behemoth'' at the heart of the Milky Way. He describes the dizzying technological advances that have recently brought us to the point of seeing through all the cosmic dust to a dark spot in a clouded cluster of stars in the constellation Sagittarius. Carefully assembling the compelling circumstantial evidence for its black hole status, he shows that it is primed to reveal itself as a glorious panorama of activity within this decade--through revolutionary images of its ''event horizon'' against the bright backdrop of nearby, radiating gas.

Uniquely, this book brings together a specific and fascinating astronomical subject--black holes--with a top researcher to provide both amateur and armchair astronomers, but also professional scientists seeking a concise overview of the topic, a real sense of the palpable thrill in the scientific community when an important discovery is imminent.

This timely book is suitable for the general reader wishing to find answers to some of the intriguing questions now being asked about black holes. Although once recognized as the most destructive force in nature, following a cascade of astonishing discoveries, the opinion of supermassive black holes has undergone a dramatic shift. Astronomers are discovering that these objects may have been critical to the formation of structure in the early universe, spawning bursts of star formation, planets, and even life itself. Fulvio Melia is Associate Head of Physics and Professor of Astronomy at the University of Arizona. He is author of Electrodynamics (University of Chicago, 2001), and a forthcoming title, The Black Hole at the Center of Our Galaxy (Princeton).

High-energy astrophysics involves the study of exceedingly dynamic and energetic phenomena occurring near the most extreme celestial objects known to exist, such as black holes, neutron stars, white dwarfs, and supernova remnants. "High-Energy Astrophysics" provides graduate and advanced undergraduate students with the most complete, self-contained introduction to the subject available. This textbook covers all the essentials, weaving together the latest theory with the experimental techniques, instrumentation, and observational methods astronomers use to study high-energy radiation from space.

Fulvio Melia introduces topics at the forefront of today's research, including relativistic particles, energetic radiation, and accretion disk theory. No other textbook offers such a thorough yet concise treatment of the key aspects of high-energy astrophysics--both theoretical and observational--or delves as deeply into modern detection techniques, satellite systems, and analytical and numerical modeling used by theoreticians. Amply illustrated, "High-Energy Astrophysics" is also ideal for researchers interested in the application of fundamental physical laws to understand how matter and radiation behave in regions of the universe where physical conditions are most extreme.Uniquely weaves together the theoretical and experimental aspects of this important branch of astronomy Features stunning images of the high-energy sky Fully describes the principal classes of high-energy sources, with an in-depth study of many archetypal objects within them Provides an excellent, self-contained resource for the classroom, written by a preeminent researcher and teacher in the field

Practically all of modern physics deals with fields--functions of space (or spacetime) that give the value of a certain quantity, such as the temperature, in terms of its location within a prescribed volume. Electrodynamics is a comprehensive study of the field produced by (and interacting with) charged particles, which in practice means almost all matter.
Fulvio Melia's "Electrodynamics" offers a concise, compact, yet complete treatment of this important branch of physics. Unlike most of the standard texts, "Electrodynamics" neither assumes familiarity with basic concepts nor ends before reaching advanced theoretical principles. Instead this book takes a continuous approach, leading the reader from fundamental physical principles through to a relativistic Lagrangian formalism that overlaps with the field theoretic techniques used in other branches of advanced physics. Avoiding unnecessary technical details and calculations, "Electrodynamics" will serve both as a useful supplemental text for graduate and advanced undergraduate students and as a helpful overview for physicists who specialize in other fields.