Open questions in classical gravity
In this work, the authors discuss some outstanding open questions regarding the validity and uniqueness of the standard second-order Newton-Einstein classical gravitational theory. On the observational side the authors discuss the degree to which the realm of validity of Newton's law of gravity can actually be extended to distances much larger than the solar system distance scales on which the law was originally established. On the theoretical side the authors identify some commonly accepted (but actually still open to question) assumptions which go into the formulation of the standard second-order Einstein theory in the first place. In particular, it is shown that while the familiar second-order Poisson gravitational equation (and accordingly its second-order covariant Einstein generalization) may be sufficient to yield Newton's law of gravity they are not in fact necessary. The standard theory thus still awaits the identification of some principle which would then make it necessary too. It is shown that current observational information does not exclusively mandate the standard theory, and that the conformal invariant fourth-order theory of gravity considered recently by Mannheim and Kazanas is also able to meet the constraints of data, and in fact to do so without the need for any so farmore »
- Publication Date:
- OSTI Identifier:
- 7158201
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Foundations of Physics; (United States); Journal Volume: 34:4
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; GRAVITATION; CLASSICAL MECHANICS; GENERAL RELATIVITY THEORY; COSMOLOGY; SOLAR SYSTEM; FIELD THEORIES; MECHANICS 661310* -- Relativity & Gravitation-- (1992-)