The search for continuous gravitational waves in LIGO and Virgo data

The detection of continuous gravitational waves is among the main targets of the LIGO and Virgo detectors. Such kind of signals, emitted e.g. by spinning neutron stars asymmetric with respect to the rotation axis, are very weak and their search poses challenging data analysis problems. In this review I will discuss the main issues regarding the search of continuous gravitational waves in the data of current interferometric detectors and some recently published results.