Forward physics results from ATLAS

The rapidity gap cross section and the dijet with jet veto analyses that were measured at the ATLAS experiment at the LHC are discussed. The rapidity gap cross section analysis measures the differential cross section as a function of the forward rapidity gap size. This diffractive cross section is compared to PYTHIA 8, PYTHIA 6 and PHOJET. The measured diffractive cross section is approximately 1mb per forward rapidity gap size for a gap size greater than 3. The dijet with jet veto analysis measures the fraction of dijet events that remain after the application of a jet veto of 20 GeV in the rapidity region between the dijet system. It is presented against the rapidity separation of the boundary dijets (in the range $0<Deltaeta < 6$) and the average transverse momentum of the boundary jets (in the range $50<ar{p_T}<500~GeV$). The data are compared POWHEG-BOX interfaced to the parton showering in PYTHIA and HERWIG, and to HEJ.