The theoretical determination of braking indices of pulsars is still an open problem. In this paper we report results of a study concerning such determination based on a modification of the canonical model, which admits that pulsars are rotating magnetic dipoles, and on data from the seven pulsars with known braking indices. In order to test the modified model, we predict ranges for the braking indices of other pulsars.

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We show that the interaction of a gravitational wave with a spherical resonant-mass antenna changes the antennaÏs shape to that of an ellipsoid. These changes in shape always determine the direction of the incoming wave and may provide information on the waveÏs polarization. We present a new approach for determining the position of astrophysical sources of gravitational waves which involves fewer calculations than in earlier methods. We also show how the measured quantities relate to the energy density of the wave.

The Mario Schenberg gravitational wave detector has been constructed at its site in the Physics Institute of the University of São Paulo as programmed by the Brazilian Graviton Project, under the full support of FAPESP (the São Paulo State Foundation for Research Support). We are preparing it for a first commissioning run of the spherical antenna at 4.2 K with three parametric transducers and an initial target sensitivity of h ∼ 2 × 10−21 Hz−1/2 in a 60 Hz bandwidth around 3.2 kHz. Here we present the status of this project.

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