We present the results of a deep wide-field near-infrared survey of the entire Pleiades cluster recently released as part of the UKIRT Infrared Deep Sky ( UKIDSS ) Galactic Clusters Survey ( GCS ) Data Release 9 ( DR9 ) .
We have identified a sample of \sim 1000 Pleiades cluster member candidates combining photometry in five near-infrared passbands and proper motions derived from the multiple epochs provided by the UKIDSS GCS DR9 .
We also provide revised membership for all previously published Pleiades low-mass stars and brown dwarfs in the past decade recovered in the UKIDSS GCS DR9 Pleiades survey based on the new photometry and astrometry provided by the GCS .
We find no evidence of K -band variability in the Pleiades members larger than \sim 0.08 mag .
In addition , we infer a substellar binary frequency of 22–31 % in the 0.075–0.03 M _ { \odot } range for separations less than \sim 100 au .
We employed two independent but complementary methods to derive the cluster luminosity and mass functions : a probabilistic analysis and a more standard approach consisting of stricter astrometric and photometric cuts .
We found that the resulting luminosity and mass functions obtained from both methods are very similar .
We derive the Pleiades mass function in the 0.6–0.03 M _ { \odot } mass range and found that it is best reproduced by a log-normal representation with a mean characteristic mass of m _ { c } = 0.24 ^ { +0.01 } _ { -0.03 } M _ { \odot } , in agreement with earlier studies and the extrapolation of the field mass function .