Pileup suppression algorithms in the Global Event Processor for the HL-LHC Upgrade of the of the ATLAS Trigger System

To mitigate the effects of pileup in $pp$ collisions at $\sqrt{s}=$ 13 TeV with the ATLAS detector at the High-Luminosity LHC (HL-LHC), several pileup suppression algorithms are considered for implementation in the Phase II Global Event Processor (GEP). This talk will present the relative performance of each algorithm and solutions to the challenges of implementing the algorithms on the firmware level.