Abstract
We present the most general covariant ghost-free gravitational action in a Minkowski vacuum. Apart from the much studied f(R) models, this includes a large class of nonlocal actions with improved UV behavior, which nevertheless recover Einstein's general relativity in the IR.
Original language | English |
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Journal | Physical Review Letters |
Volume | 108 |
Issue number | 3 |
Pages (from-to) | 031101 |
ISSN | 0031-9007 |
DOIs | |
Publication status | Published - 19 Jan 2012 |