Pulsar Spin-Down by ³P₂ Superfluid Neutron with Field Decay

To describe pulsar spin-down, we present a simple combined torque model that takes into account both the standard magnetic dipole radiation and the electromagnetic radiation from the ³P₂ superfluid vortex neutrons inside neutron star. Using an ordinary exponential model for the magnetic field decay, we derive an analytical formulae for pulsar evolution tracks. The pulsar evolution on the P-P diagram is quite different from that of the standard magnetic dipole radiation model, especially when the superfluid torque or field decay becomes dominant.