INVESTIGADORES
BARRACO DIAZ Daniel Eugenio
congresos y reuniones científicas
Título:
First Order Formalism of f(R) Gravity
Autor/es:
D. BARRACO; D. BARRACO AND V.H. HAMITY
Lugar:
Huerta Grande Córdoba
Reunión:
Congreso; GRG 13; 1992
Resumen:
The first order formalism is applied to study the field equations of a general
Lagrangian density for gravity of the form LG = √- g f(R). This field
equations correspond to theories which are a subclass of conformally metric
theories in which the derivative of the metric is proportional to the metric
by a Weyl vector field. The resulting geometrical structure is unique, except
when f(R) = aR², in the sense that the Weyl field is identifiable in terms
of the trace of the energy-momentum tensor and its derivatives. In the case
f(R) = a R² the metric is only defined up to a conformal factor. We discuss
the matter conservation equations which are implied by the invariance of the
theories under diffeomorphisms. We apply the results to the case of dust and
obtain that in general the dust particles will not follow geodesic lines. We
consider the linearized field equations and apply them to obtain the weak
field slow motion limit. It is found that the gravitational potential acquires
a new term which depends linearly on the mass density. The importance of
these new equations is briefly discussed