Dr. Vargas was an invited speaker in the meeting “Antiproton physics in the ELENA Era” organized by the Royal Society of London in Sept. 2017.  In the meeting he explained to the world leading experts in antimatter physics how they can test CPT and Lorentz symmetry in their experiments.  Testing these symmetries is the main goal of the international antimatter collaborations based at CERN such as ALPHA, ASACUSA, ATRAP, AEgIS, GBAR, and BASE.  These collaborations are studying these symmetries because any exception to them could lead to answers to some of the most puzzling questions in physics such as how to describe gravity at the quantum scale and why there is more matter than antimatter in the universe.  The ALPHA, ASACUSA, ATRAP, and BASE collaborations try to answer these questions by exploring how antimatter absorbs and emits light.  Other collaborations such as GBAR and AEgIS explore these questions by studying how gravity affects antimatter. 

Dr Vargas was also given the honor of being the first speaker at the “International Conference on Exotic Atoms and Related Topics” held by the Austrian Academy of Sciences in Sept. 2017.  In his talk he discussed how different international collaborations can test Lorentz and CPT symmetry.  This includes the antimatter collaborations at the world's largest high-energy research facility operated by CERN in France and Switzerland;  the MuSEUM muonium experiment and the muon g-2 experiment at the world-class research facility J-PARC in Japan;  the muon g-2 experiment at the Fermi National Accelerator Laboratory; the muonic-hydrogen experiment at the prestigious Paul Scherrer Institute in Switzerland; and the positronium experiment at Einstein's alma matter EHT Zurich.