This collection of papers presents ideas and problems arising over the past 100 years regarding classical and quantum gravity, gauge theories of gravity, and spacetime transformations of accelerated frames. Both Einstein''s theory of gravity and the YangOCoMills theory are gauge invariant. The invariance principles in physics have transcended both kinetic and dynamic properties and are at the very heart of our understanding of the physical world. In this spirit, this book attempts to survey the development of various formulations for gravitational and YangOCoMills fields and spacetime transformations of accelerated frames, and to reveal their associated problems and limitations. The aim is to present some of the leading ideas and problems discussed by physicists and mathematicians. We highlight three aspects: formulations of gravity as a YangOCoMills field, first discussed by Utiyama; problems of gravitational theory, discussed by Feynman, Dyson and others; spacetime properties and the physics of fields and particles in accelerated frames of reference. These unfulfilled aspects of Einstein and YangOCoMills'' profound thoughts present a great challenge to physicists and mathematicians in the 21st century."

This book shows how one can combine Yang-Mills gauge symmetry and effective Einstein-Grossmann metric tensors to tackle physical problems at microscopic, macroscopic and super-macroscopic length scales. In particular, the combination of gauge symmetry and an effective metric tensor provides a framework for and leads to an alternative dynamics of cosmic expansion based on quantum Yang-Mills gravity at the super-macroscopic limit. Together with the cosmological principle, one can investigate and derive expanding scale factors, the age of the universe, the cosmic redshift, and the Hubble recession velocity. Furthermore, this framework leads to a possible explanation for the late-time accelerated cosmic expansion due to baryon masses and charges. All these discussions are based on the operationally defined space and time coordinates of inertial frames. Finally, this book expounds on the intimate relationship between space-time translation gauge symmetry and the beautiful ideas of the Lie derivative and Pauli's variation. One interesting application of the Lie derivative is to formulate a gravitational theory with an external space-time gauge group, which leads to Yang-Mills gravity.

The ICGA series of conferences is specially aimed to serve the needs of the workers in this research area in the Asia-Pacific region. The previous conferences of this series have attracted a growing number of local, regional and international participants. 2005 was an auspicious year. Not only was it the International Year of Physics, commemorating Einstein's great achievements of 1905, it also was the anniversary of Einstein's development of General Relativity: he submitted the final form of his field equations on 25 November, 1915. Nine decades years later, around 40 Taiwan-based participants were joined by over 40 distinguished visitors from Canada, China, France, Japan, Korea, Russia, and the USA, and this volume includes many of the papers that were presented. The depth and breadth of these contributions reflect the high quality of the meeting and the development of the field in the Asia-Pacific region.

The International Conference on Gravitation and Astrophysics(ICGA) is to serve the needs of research workers in gravitation and astrophysics in the Asia-Pacific region. This proceedings covers a wide and hot area of research, including cosmological model, gravitational lensing, precision measurement of G, CMB, Kerr space-time, gravitational wave, the LISA, LIGO, LCGT projects in Japan, black hole, dark matter, Yangndash;Mills gravity, neutron star, type la supernovae, quasi-local energy, anti-de Sitter space-time.

YangOCoMills gravity is a new theory, consistent with experiments, that brings gravity back to the arena of gauge field theory and quantum mechanics in flat space-time. It provides solutions to long-standing difficulties in physics, such as the incompatibility between Einstein''s principle of general coordinate invariance and modern schemes for a quantum mechanical description of nature, and Noether''s OCyTheorem IIOCO which showed that the principle of general coordinate invariance in general relativity leads to the failure of the law of conservation of energy. YangOCoMills gravity in flat space-time appears to be more physically coherent than conventional gravity in curved space-time. The problems of quantization of the gravitational field, the operational meaning of space-time coordinates and momenta, and the conservation of energy-momentum are all resolved in YangOCoMills gravity.The aim of this book is to provide a treatment of quantum YangOCoMills gravity, with an emphasis on the ideas and evidence that the gravitational field is the manifestation of space-time translational symmetry in flat space-time, and that there exists a fundamental space-time symmetry framework that can encompass all of physics, including gravity, for all inertial and non-inertial frames of reference.