Within the Uppsala high energy physics division, my team and I (a PhD student and myself + some master/project students) are working on Dark Sector Searches with the ATLAS experiment at the LHC. Dark Sectors are hidden collections of new particles and forces that could explain Dark Matter, the biggest experimental puzzle in contemporary physics. We follow this theory papers: https://arxiv.org/abs/1809.10183, and https://arxiv.org/abs/1809.10184. The final states in which we are working: ttbb, and tttb, suffer from very large background and occupy enormous datasets.