Application of a two dipole model to PSR J1640-4631, a pulsar with an anomalous braking index

Hui Shi, Hong-Wei Hu, Wen-Cong Chen

Recent timing observation provides an intriguing result for the braking index of the X-ray pulsar PSR J1640-4631, which has a measured braking index $n=3.15\pm 0.03$. The decrease o…