Eleny-Nicoleta Ionel (born April 1969) is a Romanian mathematician whose research concerns symplectic geometry, including the study of the Gromov–Witten invariants and Gopakumar–Vafa invariants. Among her most significant results are the proofs of Gopakumar-Vafa conjectures (joint with Thomas H. Parker et. al.), and the proof of Getzler's conjecture, asserting vanishing in codimension at least g of the tautological ring of the moduli space of genus-g curves.
She is a professor of mathematics at Stanford University, where she was chair of the mathematics department from 2016 to 2019.[1]