e/Test particle

Information
has gloss	eng: In physical theories, a test particle is an idealized model of an object whose physical properties (usually mass, charge, or size) are assumed to be negligible except for the property being studied, which is considered to be insufficient to alter the behavior of the rest of the system. The concept of a test particle often simplifies problems, and can provide a good approximation for physical phenomena. In addition to its uses in the simplification of the dynamics of a system in particular limits, it is also used as a diagnostic in computer simulations of physical processes.
lexicalization	eng: test particle
instance of	c/Mathematical methods in general relativity

Meaning
French
has gloss	fra: En relativité générale on appelle particule test un corps dont la masse ou plus généralement lénergie est trop faible pour affecter significativement la métrique de lenvironnement dans lequel elle se déplace. Cette métrique est alors appelée métrique de fond. Les particules tests sont utiles car les trajectoires décrivant leur évolution sont des géodésiques pour la métrique de fond.
lexicalization	fra: Particule test