GRAVITATIONAL SHAPIRO PHASE-SHIFT ON THE PERIOD OF THE PULSARS TO DETECT DARK-MATTER

The Shapiro phase shift on pulsars (SPSP) influences, at a low but det ectable level, the periods of pulsars (PSRs) and the derivatives of th e periods. This effect may be already written in the time derivative d eviation of pulsars and in particular it may explain the presence of a few negative pulsar derivatives among 558 known PSRs, We describe in detail the phenomenon and predict that the SPSP may play a role in P d eviations for just a few PSRs a year ( similar to 0.5-5 event yr(-1)) at a P similar to (10-(14)-10-(15)) s s(-1) level, leading to a plausi ble explanation for the puzzling negative pulse derivative of few peri ods of PSRs, Analogous collective SPSP in globular clusters (GCs) is p ossible.