Analytic hypoellipticity for sums of squares and the Treves conjecture

Hypoelliptic second order differential equations

Lars Hörmander · Acta Mathematica · 1967 · 2.4K citations · Full text

Natural Sciences, Mathematics, Differential Equations +5

Uniqueness theorems and wave front sets for solutions of linear differential equations with analytic coefficients

Lars Hörmander · Communications on Pure and Applied Mathematics · 1971 · 218 citations

Natural Sciences, Mathematics, Differential Equations +14

The analysis of partial differential operators

Gian‐Carlo Rota · Advances in Mathematics · 1986 · 188 citations

Natural Sciences, Mathematics, Physics +12

Analytic hypo-ellipticity of a class of pseudodifferential operators with double characteristics and applications to the -neumann problem

François Trèves · Communications in Partial Differential Equations · 1978 · 146 citations

Natural Sciences, Physics, Differential Equations +10

Nonanalytic-hypoellipticity for some degenerate elliptic operators

M. S. Baouendi, C. Goulaouic · Bulletin of the American Mathematical Society · 1972 · 93 citations · Full text

Natural Sciences, Mathematics, Dynamical Systems +6