标题： 四维共形引力、 confinement 和星系旋转曲线 显示英文标题

标题： Four Dimensional Conformal Gravity, Confinement, and Galactic Rotation Curves

摘要： 我们回顾了最近由曼海姆和卡赞纳提出的共形不变的四阶引力理论，它作为爱因斯坦标准二阶理论的候选替代理论得到了发展。我们考察了原则上如何在保留爱因斯坦理论已验证特征的同时完全取代它，并借鉴粒子物理学的智慧提出了一个完全协变且共形不变的替代理论。我们将这一理论视为基本粒子的微观基础理论，从而赋予曲率在基本粒子动力学中更重要的角色，特别是与基本粒子质量的产生以及被认为是描述它们的扩展袋状模型相关。我们讨论了共形引力在多大程度上能够与弦理论竞争，作为一个一致的引力微观理论候选者。此外，我们还探索了这一理论作为一种宏观引力理论的可能性，在这种理论中，精确的非微扰的经典势具有共形不变的$V(r)=-\beta /r+\gamma r/2$形式，这种形式使我们能够解释星系旋转曲线的一般规律性，而无需假设大量暗物质的存在；并且这种解释似乎与当前的微透镜观测结果不冲突。 显示英文摘要

摘要： We review the current status and prospects for the conformal invariant fourth order theory of gravity which has recently been advanced by Mannheim and Kazanas as a candidate alternative to the standard second order Einstein theory. We examine how it is possible in principle to replace the Einstein theory at all while retaining its tested features, and we appeal to the wisdom gleaned from particle physics to suggest a fully covariant, conformal invariant alternative. We explore the theory as a microscopic fundamental theory of elementary particles, to thus give curvature a more prominent role in elementary particle dynamics, and in particular in the generation both of elementary particle masses and the extended bag-like models which are thought to describe them. We discuss the degree to which conformal gravity can compete with string theory as a consistent candidate microscopic theory of gravity. Additionally, we explore the theory as a macroscopic theory of gravity where the exact, non-perturbative, classical potential is found to be of the confining $V(r)=-\beta /r+\gamma r/2$ form, a form which enables us to provide an explanation for the general systematics of galactic rotational velocity curves without the need to assume the existence of copious amounts of dark matter; with this explanation of the curves apparently not being in conflict with the current round of microlensing observations.