1. A possible model of pulsar timing
Biping Gong
Collaborator Yaping Li
KIAA Oct 19, 2012

2. quasi-periodic feature?

3. Possible mechanisms free precession exact period un-modeled companion
Random processes
quasi-periodic feature? multi-planets ?

4. Long-term orbital effects?
geodetic precession of spin axis , BO equation
Like the effect of free precession, it also predicts a periodic timing delay, without considering the motion of the orbital plane.

6. BO’s two-body equation
negligible

7. AK’s two-body equation (J=const)
J=L+S=const
（J=const ?）
Just with the basic binary parameters like, orbital
period, mass, and spin parameters like, spin angular
momentum, we have the following results.

9. PSR B

11. PSR B

13. PSR B

14. PSR B

15. PSR J

16. Companion star? Are there binary pulsars with
Spin angular momentum，
Orbital period， hr
Companion mass， solar mass
Are there binary pulsars with
orbital period less than 90min ?

17. 4U 1626-67 an evidence of such a scenario?

20. Thanks!