title: New post-Newtonian parameter to test Chern-Simons gravity.
abstract: We study Chern-Simons (CS) gravity in the parametrized post-Newtonian (PPN) framework through a weak-field solution of the modified field equations. We find that CS gravity possesses the same PPN parameters as general relativity, except for the inclusion of a new term, proportional to the CS coupling and the curl of the PPN vector potential. This new term leads to a modification of frame dragging and gyroscopic precession and we provide an estimate of its size. This correction might be used in experiments, such as Gravity Probe B, to bound CS gravity and test string theory.
authors.affiliation: Institute for Gravitational Physics and Geometry, Center for Gravitational Wave Physics and Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Stephon
authors.initials: S
authors.lastname: Alexander
authors.forename: Nicolas
authors.initials: N
authors.lastname: Yunes