Experimental clues on pulsar energy losses and the role of circumpulsar supernova fallback disks

Positron measurements in cosmic rays, studies of gravitational wave emission from isolated pulsars and observations of circumpulsar supernova fallback disks allow us to set upper limits on several energy loss mechanisms of young and mature pulsars. Presently, the above experimental evidences do not lead to conflicting scenarios. In particular, we focus on pulsar spin down due to friction or propeller torque from supernova fallback disks. Gravitational wave emission from circumpulsar planetary systems or precessing disks does not play a relevant role in pulsar spin down. However, the detection of gravitational waves from these systems with future space interferometers would allow us to estimate the fraction of pulsars surrounded by disks. While the planetary system detection appears to be unfeasible, the DECI-Hertz Interferometer Gravitational Wave Observatory (DECIGO) and the Big Bang Observatory (BBO) might reveal the presence of precessing disks.