Some considerations on the present-day results for the detection of frame-dragging after the final outcome of GP-B
Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR)-Istruzione and International Institute for Theoretical Physics and High Mathematics Einstein-Galilei (IITPM)
Accepted: 5 August 2011
The cancellation of the first even zonal harmonic coefficient J2 from the linear combination f(2L) of the nodes Ω of LAGEOS and LAGEOS II used in the latest tests of the Lense-Thirring effect cannot be perfect, contrary to what assumed so far. It is so also because of the uncertainties in the spatial orientation of the terrestrial spin axis . As a consequence of above, the coefficient c1 entering f(2L), which is not a solve-for parameter being, instead, theoretically computed from the analytical expressions of the classical node precessions due to J2, is, on average, uncertain at a 10−8 level over multi-decadal time spans ΔT comparable to those used in the data analyses performed so far. A further ≃20% systematic uncertainty, thus, occurs. The shift ΔρLT due to the gravitomagnetic frame-dragging on the station-spacecraft range ρ is numerically computed over ΔT=15 d and ΔT=1 y. The need to look at such a directly observable quantity is highlighted, along with some critical remarks concerning the methodology used so far to measure the Lense-Thirring effect with the LAGEOS satellites. Suggestions for a different, more trustable and reliable approach are offered.
PACS: 04.80.-y – Experimental studies of gravity / 04.80.Cc – Experimental tests of gravitational theories / 91.10.Sp – Satellite orbits
© EPLA, 2011