Nonlocal gravity with worldline inversion symmetry
Steven Abel, Luca Buoninfante, Anupam Mazumdar
Abstract
We construct a quadratic curvature theory of gravity whose graviton propagator around the Minkowski background respects wordline inversion symmetry, the particle approximation to modular invariance in string theory. This symmetry automatically yields a corresponding gravitational theory that is nonlocal, with the action containing infinite order differential operators. As a consequence, despite being a higher order derivative theory, it is ghost-free and has no degrees of freedom besides the massless spin-2 graviton of Einstein’s general relativity. By working in the linearised regime we show that the point-like singularities that afflict the (local) Einstein’s theory are smeared out.
Topics & Concepts
GravitonMinkowski spacePhysicsGravitational singularityGeneral relativityMathematical physicsGravitationPropagatorEinsteinMassless particleString theoryQuantum gravityCurvatureModular invarianceSymmetry (geometry)Theoretical physicsClassical mechanicsQuantum mechanicsMathematicsGeometryQuantumModular designComputer scienceOperating systemBlack Holes and Theoretical PhysicsCosmology and Gravitation TheoriesNoncommutative and Quantum Gravity Theories