Physical Review Letters · 2012 · 744 citations · 18 references
Natural SciencesPhysicsGravitationGravityTheoretical PhysicsCurved SpacetimeEinstein Field EquationsGauge TheoryGeneral RelativitySpacetime GeometrySpecial RelativityAsymptotically Flat SpacetimesCosmology In General RelativityF(r) GravityGeneral Relativity In CosmologyMinkowski SpaceSingularity Theorems In Cosmology
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.
18
Non-commutative geometry and string field theory
Edward Witten · Nuclear Physics B · 1986 · 2K citations
Bouncing universes in string-inspired gravity
Journal of Cosmology and Astroparticle Physics · 2006 · 481 citations · Full text
Natural Sciences, Physics, Cosmology +11
On ghost-free tensor Lagrangians and linearized gravitation
P. van Nieuwenhuizen · Nuclear Physics B · 1973 · 380 citations
P. Freund, Edward Witten · Physics Letters B · 1987 · 341 citations