Diego Altamirano
Accretion-powered millisecond X-ray pulsars (AMXPs) had been predicted in the early 1980s as the progenitors of millisecond radio pulsars. However, it was not until 1998 that the first AMXP was discovered. Since then, a total of 13 AMXPs have been found out of the >150 Low-mass X-ray binaries (LMXB) known up to date. Albeit the many theoretical efforts that have been made to explain the lack of pulsation in the persistent X-ray emission of the majority of LMXBs, the reason why only ~10% of the neutron star systems are pulsars is still under debate. In this talk I will summarize the last 13 years of discoveries and present results on three pulsars that might help us understand why not all LMXBs pulsate.