Results of a search for new phenomena in final states with an energetic jet
and large missing transverse momentum are reported. The search uses proton-proton
collision data corresponding to an integrated luminosity of 36.1 fb−1 at a centre-of-mass
energy of 13 TeV collected in 2015 and 2016 with the ATLAS detector at the Large Hadron
Collider. Events are required to have at least one jet with a transverse momentum above
250 GeV and no leptons (e or µ). Several signal regions are considered with increasing
requirements on the missing transverse momentum above 250 GeV. Good agreement is
observed between the number of events in data and Standard Model predictions. The
results are translated into exclusion limits in models with pair-produced weakly interacting
dark-matter candidates, large extra spatial dimensions, and supersymmetric particles in
several compressed scenarios.