Gary Feldman's research interests are in the experimental study of neutrino oscillations. Currently he is working on the NOvA Experiment at Fermilab. NOvA is a two-detector experiment, which compares the signals observed in a near detector on the Fermilab site with those observed in a 14-kiloton far detector 500 miles north near the Canadian border in northern Minnesota. The goal of the experiment is to make precise measurements of the oscillation parameters, including the ordering of the neutrino masses and the extent of CP violation in the lepton sector, and to search for physics beyond the standard model.

The NOvA experiment started taking data in 2016 and is scheduled to continue taking data until 2027.  Professor Feldman was the co-spokesperson for the NOvA experiment for 11 years during the period of design, construction, commissioning, and early data taking.

Although Professor Feldman is still active in the NOvA experiment, he is now retired and is not taking on students or postdocs.