Properties of spacetimes that are asymptotically flat at timelike infinity
Properties of spacetimes that are asymptotically flat at timelike infinity
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在类时无穷大时渐近平坦的时空性质
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
C. Cutler
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文献类型：
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作者：
C. Cutler
受Friedrich(1988)近期工作的启发，作者研究了在未来零点和类时无限处渐近平坦的一类时空(Afti时空)。Afti时空的定义类似于Ashtekar-Hansen(1978)对空间无限的处理中的AEFANSI时空的定义，但非物理度规要求在i+是Cinfinity，而不是在i0是C>；0。给定I+已经附加的时空，他证明了对I+的进一步扩展是唯一确定的。对于应力能有适当渐近衰减的Afti时空，可以选择共形因子来表示I+附近的非物理度规为平坦度规加上在边界上消失的光滑片。应用这个规范条件，他证明了这种Afti时空的渐近对称代数与Poincare代数重合，计算了Bondi4动量在I+处趋近于零的速率，并证明了满足Eardley-Sachs(1973)大多数条件的射影类时无穷大可以附加到这种Afti时空上。
Motivated by recent work by Friedrich (1988) the author studies the class of spacetimes that are asymptotically flat at future null and timelike infinity (AFTI spacetimes). The definition of AFTI spacetimes is analogous to that of AEFANSI spacetimes in the Ashtekar-Hansen (1978) treatment of spatial infinity, but the unphysical metric is required to be Cinfinity at i+ as opposed to C>0 at i0. Given a spacetime to which I+ has already been attached, he proves that the further extension to i+ is uniquely determined. For AFTI spacetimes with suitable asymptotic stress-energy fall off, it is shown that the conformal factor may be chosen to represent the unphysical metric near i+ as a flat metric plus a smooth piece that vanishes on the boundary. Applying this gauge condition, he proves that the asymptotic symmetry algebra of such AFTI spacetimes coincides with the Poincare algebra and calculates the rate at which the Bondi 4-momentum approaches zero at i+, and shows that a projective timelike infinity satisfying most of the Eardley-Sachs (1973) conditions can be attached to such AFTI spacetimes.