By the mid 1960s the theory of singular integrals was firmly established by Calder�n's contributions to the theory of differential equations, including his proof of the " uniqueness in the Cauchy problem " using algebras of singular integral operators, his reduction of elliptic boundary value problems to singular integral equations on the boundary ( " the method of the Calder�n projector " ), and the crucial role played by algebras of singular integrals ( through the work of Calder�n s student R . Seeley ) in the " initial proof of the Atiyah-Singer Index Theorem ", see also the Commentary by Paul Malliavin . and Calder�n s proof of the " boundedness of the first commutator ".
32.
By the mid 1960s the theory of singular integrals was firmly established by Calder�n's contributions to the theory of differential equations, including his proof of the " uniqueness in the Cauchy problem " using algebras of singular integral operators, his reduction of elliptic boundary value problems to singular integral equations on the boundary ( " the method of the Calder�n projector " ), and the crucial role played by algebras of singular integrals ( through the work of Calder�n s student R . Seeley ) in the " initial proof of the Atiyah-Singer Index Theorem ", see also the Commentary by Paul Malliavin . and Calder�n s proof of the " boundedness of the first commutator ".
