PT3 - Precision Tests at Sub-Millimeter Distances |
Speaker_ |
Lusanna, Luca |
Talk _ |
Dynamical clock synchronization in Einstein's theory: implications for the ESA ACES mission |
Abstract _ |
Given any solution of Einstein's equations in a coordinate system, the associated extrinsic curvature tensor in that coordinate system is uniquely determined. The 3+1 splitting of the spacetime, whose spacelike leaves have such an extrinsic curvature, can be determined with an inverse problem. The resulting leaves are both Cauchy surfaces for the given solution and simultaneity surfaces, namely a dynamical convention for the synchronization identifying a notion of instantaneous 3-space. The implications for the IAU conventions in the solar system and for the determination of the time delay of signals between an Earth station and the space station (to be measured in the ACES mission of ESA) are discussed |