The paper studies the local solvability and subellipticity for square systems of principal type. These are the systems for which the principal symbol vanishes of first order on its kernel. For systems of principal type having constant characteristics, local solvability is equivalent to condition (Ψ) on the eigenvalues. This is a condition on the sign changes of the imaginary part along the oriented bicharacteristics of the real part of the eigenvalue. In the generic case when the principal symbol does not have constant characteristics, condition (Ψ) is not sufficient and in general not well defined. Instead we study systems which are quasi-symmetrizable, these systems have natural invariance properties and are of principal type. We prove th...
We give a proof of the Nirenberg-Treves conjecture: that local solvability of principal-type pseudo-...
It was a great surprise when Hans Lewy in 1957 presented a non-vanishing complex vector field that i...
This paper deals with the (micro)local C ∞ hypoellipticity of the solutions of of some classes of ov...
This paper studies the solvability for square systems of classical pseudodifferential operators. We ...
We study the solvability for a system of pseudodifferential operators. We will assume that the syste...
The pseudospectrum (or spectral instability) of non-self-adjoint operators is a topic of current int...
We give a new proof of the Nirenberg-Treves conjecture: that local solvability of principal type pse...
We give a new proof of the Nirenberg-Treves conjecture: that local solvability of principal type pse...
We give a proof of the Nirenberg-Treves conjecture: that local solvability of principal type pseudod...
The purpose of this paper is to study microlocal conditions for inclusion relations between the rang...
In this paper we consider the solvability of pseudodifferential operators in the case when the princ...
We will show a local solvability result for a class of degenerate second order linear partial differ...
It is given a short elementary proof of the localized subelliptic estimates for non-degenerate pseud...
AbstractIt is shown that a sufficient condition for the local solvability of an operator P(x, Dx) = ...
Let p(x,D) be a pseudodifferential operator on Rn with a ( formal) analytic symbol p(x, ξ), and let ...
We give a proof of the Nirenberg-Treves conjecture: that local solvability of principal-type pseudo-...
It was a great surprise when Hans Lewy in 1957 presented a non-vanishing complex vector field that i...
This paper deals with the (micro)local C ∞ hypoellipticity of the solutions of of some classes of ov...
This paper studies the solvability for square systems of classical pseudodifferential operators. We ...
We study the solvability for a system of pseudodifferential operators. We will assume that the syste...
The pseudospectrum (or spectral instability) of non-self-adjoint operators is a topic of current int...
We give a new proof of the Nirenberg-Treves conjecture: that local solvability of principal type pse...
We give a new proof of the Nirenberg-Treves conjecture: that local solvability of principal type pse...
We give a proof of the Nirenberg-Treves conjecture: that local solvability of principal type pseudod...
The purpose of this paper is to study microlocal conditions for inclusion relations between the rang...
In this paper we consider the solvability of pseudodifferential operators in the case when the princ...
We will show a local solvability result for a class of degenerate second order linear partial differ...
It is given a short elementary proof of the localized subelliptic estimates for non-degenerate pseud...
AbstractIt is shown that a sufficient condition for the local solvability of an operator P(x, Dx) = ...
Let p(x,D) be a pseudodifferential operator on Rn with a ( formal) analytic symbol p(x, ξ), and let ...
We give a proof of the Nirenberg-Treves conjecture: that local solvability of principal-type pseudo-...
It was a great surprise when Hans Lewy in 1957 presented a non-vanishing complex vector field that i...
This paper deals with the (micro)local C ∞ hypoellipticity of the solutions of of some classes of ov...