Loss of angular momentum in a binary system due to collisionless particles as monopoles or gravitinos: Does it exceed the gravitational radiation emission in the binary system PSR 1913 +16?

We consider the gravitational drag for a massive object moving in the (almost) collisionless fluid made by magnetic monopoles: the drag mechanism may be relevant in the loss of angular momentum in binary systems; in particular for a known binary system in our galaxy associated with pulsar PSR 1913 + 16 we show that a monopole number density larger than 10-7 cm-3 (as the expected solar one) may induce an energy loss comparable or even larger than the one indebt to the gravitational radiation of the system.