LARES/WEBER-SAT and the equivalence principle

TL;DR

The paper argues that the LARES/WEBER-SAT satellite cannot significantly improve the testing accuracy of the equivalence principle beyond current levels, contrary to recent claims suggesting two orders of magnitude improvement.

Contribution

It critically assesses the claimed potential of LARES/WEBER-SAT to enhance equivalence principle tests, showing the actual achievable accuracy is much lower.

Findings

Achievable accuracy is around 10^-9, not 10^-15 as claimed.

Recent claims of two orders of magnitude improvement are unsubstantiated.

The satellite's potential for testing the equivalence principle is limited by fundamental constraints.

Abstract

It has often been claimed that the proposed Earth artificial satellite LARES/WEBER-SAT-whose primary goal is, in fact, the measurement of the general relativistic Lense-Thirring effect at a some percent level-would allow to greatly improve, among (many) other things, the present-day (10^-13) level of accuracy in testing the equivalence principle as well. Recent claims point towards even two orders of magnitude better, i.e. 10^-15. In this note we show that such a goal is, in fact, unattainable by many orders of magnitude being, instead, the achievable level of the order of 10^-9.