Digging in through the Equivalence Principle

L. KRAISELBURD, H. VUCETICH

La Cumbre

Congreso; Grav 11; 2011

FaMAF - Universidad Nacional de Córdoba

<!-- @page { margin: 2cm } P { margin-bottom: 0.21cm } --> A. Einstein claimed the Equivalence Principle (EP) in his book, ``How I Constructed the Theory of Relativity´´ such that,  ``A little reflection will show that the law of the equality of the inertial and gravitational mass is equivalent to the assertion that the acceleration imparted to a body by a gravitational field is independent of the nature of the body...  ... It is only when there is numerical equality between the inertial and gravitational mass that the acceleration is independent of the nature of the body.´´  From this principle follows both the Universality of Free Fall (UFF) and Local Lorentz Invariance (LLI), thus fulfilling the equality between inertial mass, passive mass and rest mass. Another profound consequence is that all forms of non-gravitational energy, which contribute to the inertial mass, should couple in the same way to the gravitational field. Any violation of the UFF can be described with a non-zero difference between inertial mass and passive mass, which can be expressed via nuclear binding energies and phenomenological parameters specific to each type of interaction reflecting its degree of violation to the EP. Since these parameters are measured in Eotvos-like experiments, then these last ones can set an upper limit on the difference of acceleration in a gravitational field for different materials and so impose upper bounds on the ``violation parameters´´. To further examine the accuracy of present Eotvos experiments, we shall attempt to set up modern independent bounds on violation of the EP by the four known fundamental forces.