Comparing causality principles

Abstract

The principle of common cause is discussed as a possible fundamental principle of physics. Some revisions of Reichenbach's formulation of the principle are given, which lead to a version given by Bell. Various similar forms are compared and some equivalence results proved. The further problems of causality in a quantal system, and indeterministic causal structure, are addressed, with a view to defining a causality principle applicable to quantum gravity.

27 pages, 1 figure. Some mistakes corrected, discussions expanded, and a reference added. In new version, some notation and wording changed, another new reference added; now closer to published version