Slowing Down and Speeding Up PSR's Periods: A Shapiro Telescope tracing Dark Matter

Abstract

Dark matter influence globally galactic Keplerian motions and individually, by microlensing, star's acromatic luminosities. Moreover gravity slows down time as probed by gravitational redshift. Therefore pulsar's (PSR's) periods may record, by slowing and speeding up, any Dark MACHO crossing along the line-of-sight. This phase delay, a Shapiro Phase Delay, is a gravitational integral one and has been probed since 1964 on planets by radar echoes. We discovered in PSRs catalog a few rare PSRs (with negative period derivatives) consistent with speeding up by Shapiro delay due to MACHOs. We propose to rediscover the Shapiro effect on our solar system (for Jupiter, Mars, Sun) to calibrate a new "Shapiro Telescope Array" made by collective monitoring of the sample of PSRs along the ecliptic plane.