INVESTIGADORES
BARRACO DIAZ Daniel Eugenio
artículos
Título:
Conservation Laws, Symmetry Properties and Equivalence Principle in a Class of Alternative Theories of Gravity
Autor/es:
DANIEL BARRACO, EDUARDO DOMINGUEZ, ROBERTO GUIBERT
Revista:
PHYSICAL REVIEW D - PARTICLE AND FILDS
Referencias:
Año: 1999 vol. 60 p. 440121 - 440128
ISSN:
0556-2821
Resumen:
We consider a subclass of alternative theories of gravitation obtained by a first order formalism from a Lagrangian density LT=f(R)sqrt[-g]+LM where the matter field Lagrangian density LM
does not depend on the connection. For this theory we derive an
analogue of the Einstein pseudotensor and the von Freud superpotential.
Then we derive, using the arbitrariness that is always present in the
choice of pseudotensor and superpotential, a generalization of the
Møller superpotential as associated with a double-index differential
conservation law. This superpotential allows us to deduce that there
are two analogues of the Komar vector of general relativity (GR): one
associated with the general connection and the other with the metric
connection. Astonishingly both of them satisfy the physical condition
that the inertial mass must be equal to the gravitational (active) mass
for any class of matter. We also obtain a generalization of Tolmans
expression for the energy, and prove that those theories with f(0)=0
share with GR the property that the total energy is independent of any
two-dimensional surface which encloses the support of the matter
distribution.