标题： 膜世界动力学与共形 bulk 场 显示英文标题

标题： Brane World Dynamics and Conformal Bulk Fields

摘要： 在Randall-Sundrum场景下，我们研究了当物质场存在于bulk时，球对称3维膜世界的动力学。 为了分析5维爱因斯坦方程，我们采用了全局保角变换，其因子表征了$Z_2$对称的翘曲。 我们找到了一组新的精确的动力坍缩解，这些解在应力-能量张量具有共形权重-4且翘曲因子仅依赖于第五维度坐标的情况下，使引力局域化在膜附近。 描述非均匀尘埃和广义暗辐射在膜上动力学的几何结构被证明属于这组解。 针对这些例子讨论了奇点或整体正则行为的条件以及静态边缘束缚极限。 此外，还明确展示了与4维观察者的有效观点完全一致，该观察者被限制在膜上，并对bulk自由度做出相同的假设。 显示英文摘要

摘要： In the Randall-Sundrum scenario we investigate the dynamics of a spherically symmetric 3-brane world when matter fields are present in the bulk. To analyze the 5-dimensional Einstein equations we employ a global conformal transformation whose factor characterizes the $Z_2$ symmetric warp. We find a new set of exact dynamical collapse solutions which localize gravity in the vicinity of the brane for a stress-energy tensor of conformal weight -4 and a warp factor that depends only on the coordinate of the fifth dimension. Geometries which describe the dynamics of inhomogeneous dust and generalized dark radiation on the brane are shown to belong to this set. The conditions for singular or globally regular behavior and the static marginally bound limits are discussed for these examples. Also explicitly demonstrated is complete consistency with the effective point of view of a 4-dimensional observer who is confined to the brane and makes the same assumptions about the bulk degrees of freedom.