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We report on an analysis of the Extended Chandra Deep Field South (E-CDFS)region using archival data from the Very Large Array, with the goal of studyingradio variability and transients at the sub-mJy level. The 49 epochs of E-CDFSobservations at 1.4 GHz sample timescales from one day to 3 months. We findthat only a fraction (1%) of unresolved radio sources above 40 uJy are variableat the 4-sigma level. There is no evidence that the fractional variabilitychanges along with the known transition of radio source populations below onemilliJansky. Optical identifications of the sources show that the variableradio emission is associated with the central regions of an active galacticnucleus or a star-forming galaxy. After a detailed comparison of the efficacyof various source-finding algorithms, we use the best to carry out a transientsearch. No transients were found. This implies that the areal density oftransients with peak flux density greater than 0.21 mJy is less than 0.37deg^-2 (at a confidence level of 95%). This result is approximately an order ofmagnitude below the transient rate measured at 5 GHz by Bower et al. (2007) butit is consistent with more recent upper limits from Frail et al. (2012). Ourfindings suggest that the radio sky at 1.4 GHz is relatively quiet. Formulti-wavelength transient searches, such as the electromagnetic counterpartsto gravitational waves, this frequency may be optimal for reducing the highbackground of false positives.

Sensitive Search For Radio Variables And Transients In The Extended Chandra Deep-Field South