arXiv subjects

Shyan-Ming Perng

Publications and source records attributed to Shyan-Ming Perng.

2 recordsLinked to original sources

arXiv1998

On Conserved Quantities at Spatial Infinity

There is a well-known short list of asymptotic conserved quantities for a physical system at spatial infinity. We search for new ones.This is carried outwithin the asymptotic framework of Ashtekar and Romano, in which spatial infinity is represented as a smooth boundary of space-time. We first introduce, for physical fields on space-time,a characterization of their asymptotic behavior as certain fields on this boundary. Conserved quantities at spatial infinity, in turn, are constructed from these fields. We find,in Minkowski space-time, that each of a Klein-Gordon field, a Maxwell field, and a linearized gravitational field yields an entire hierarchy of conserved quantities. Only certain quantities in this hierarchy survive into curved space-time.

gr-qc↗

arXiv1994

Total Mass-Momentum of Arbitrary Initial-Data Sets in General Relativity

For an asymptotically flat initial-data set in general relativity, the total mass-momentum may be interpreted as a Hermitian quadratic form on the complex, two-dimensional vector space of ``asymptotic spinors''. We obtain a generalization to an arbitrary initial-data set. The mass-momentum is retained as a Hermitian quadratic form, but the space of ``asymptotic spinors'' on which it is a function is modified. Indeed, the dimension of this space may range from zero to infinity, depending on the initial data. There is given a variety of examples and general properties of this generalized mass-momentum.

gr-qc↗