Equivalence Principle in Chameleon Models

SUSANA LANDAU; LUCILA KRAISELBURD; MARCELO SALGADO; DANIEL SUDARSKY

Sexto

Workshop; Varying fundamental constants and dynamical dark energy; 2013

Sexten Center for Astrophysics INAF - Osservatorio Astronomico di Trieste

Most theories that predict time and/or space variation of fundamental constants also predict violations of the Weak Equivalence Principle (WEP). Khoury and Weltmann proposed the chameleon model in 2004 and claimed that this model avoids experimental bounds on WEP. We present a contrasting  view  based  on an  approximate calculation of the two body problem for the chameleon field and show that the force depends on the test body composition. Furthermore, we compare the prediction of the force on a test body with Eötvös type experiments and find that the chameleon field effect cannot account  for current bounds.