Casual Sets and the Quantum Action

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The struggle between local and global concepts in physics comes to a head in  causal set quantum gravity. Local physics -- and general relativity in particular -- must be recovered in a continuum approximation if the theory is to  be successful but causal sets are inherently non-local entities. I will describe a family of causal set actions labelled by dimension, each of which is nonlocal and yet, when applied to certain causal sets, approximates the Einstein Hilbert action and is therefore effectively local.  I will explain why this is a source of hope that causal set theory has a continuum approximation.