SCALAR GRAVITATIONAL-WAVES AND OBSERVATIONAL LIMITATIONS FOR THE ENERGY-MOMENTUM TENSOR OF A GRAVITATIONAL-FIELD

From the point of view of a totally nonmetric model of the theory of gravitational interaction, i.e., in the bounds of a consistent dynamic description of gravitation (gravidynamics) a possibility is pointed out of additional loss of energy for the radiation of scalar gravitational waves. Such a radiation arises due to (in particular, periodic) variations, for example, spherically-symmetric pulsations, in a radiating system and is connected with time change of kinetic energy of system. The scalar gravitational 'luminosity' in gravidynamics is of the same order (is similar to G/c5) as the system energy loss for the radiation of 'usual' tensor gravitational waves of general relativity. Perhaps, for a binary system with a nonzero eccentricity it is necessary to account for the influence of scalar radiation on a secular variation of the companion's orbit parameters. The contribution of the scalar radiation into a total gravitational 'luminosity' of the system with a radio pulsar PSR 1913 + 16 can be of the value about 2.2% of the radiation power of the tensor gravitational waves. It can have a considerable effect at measurements of the fall rate of orbital period (P(b)) of the binary system, and the corresponding contribution into P(b) can be equal to DELTAP(b) almost-equal-to -0.053 x 10(-12) s s-1.