In the 1960s Hermann worked on elementary particle physics and quantum field theory, and published books which revealed the interconnections between vector bundles on Riemannian manifolds and gauge theory in physics, before these interconnections became "common knowledge" among physicists in the 1970s.
Born in Brooklyn, Hermann studied in Paris and at Princeton University, where he attended lectures by Charles Ehresmann and where in 1955 under Donald Spencer he received his PhD with thesis The Differential geometry of homogeneous spaces.
Following the French school of Élie Cartan, Hermann published numerous books on differential geometry and Lie group theory and their applications to differential equations, integrable systems, control theory, and physics.
One of my overall motives in writing my series of books "Interdisciplinary Mathematics" was to facilitate this flow...[despite] high structural and mental barriers to such cross-fertilization.
[2]The blue series considered history of differential geometry and Lie theory, and edited, with extensive new commentary, the work of Sophus Lie,[3] Gregorio Ricci-Curbastro and Tullio Levi-Civita,[4] Felix Klein's Vorlesungen über Mathematikgeschichte,[5] Élie Cartan,[6] Georges Valiron[7] and the contributions to invariant theory by David Hilbert.