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Showing papers by "Roger Penrose published in 1982"


Journal ArticleDOI
TL;DR: In this paper, a new approach to defining energy-momentum and angular momentum in general relativity is presented which avoids some of the difficulties of previous definitions and which can be applied quasi-locally.
Abstract: A new approach to defining energy-momentum and angular momentum in general relativity is presented which avoids some of the difficulties of previous definitions and which can be applied quasi-locally. It depends on the construction of a twistor space T α ( S ) associated with any spacelike topological 2-sphere S . Though several problems of interpretation remain to be solved, the new definition works well at I + , reproducing the Bondi-mass-momentum as four of the ten precisely determined quantities at each cut of I + . The remaining six quantities provide a definition of angular momentum which appears to be new.

375 citations


Book ChapterDOI
01 Jan 1982
TL;DR: The singularity theorems of general relativity have been studied in the context of space-time singularities as mentioned in this paper, which are regions of the universe referred to as singularities.
Abstract: We know from the “singularity theorems” of general relativity that any universe model which is compatible with the standard interpretation of background radiation and radio source counts, and which satisfies Einstein’s equations with physically reasonable assumptions about the positivity of matter density and absence of closed timelike curves, must be singular. Thus the big bang is “stable” in the sense that perturbations away from exact symmetry cannot remove the singularity. Likewise the singularities of gravitational collapse are stable in the same sense. Thus, physics as we presently understand it is limited in its scope and some new physical ideas are needed in order that the regions of the universe referred to as “space-time singularities” can be treated according to the methods of science.

4 citations