3 citations · 3 across the 7 of their papers we have counts for
7 papers
On the Microlocal Regularity of the Gevrey Vectors for second order partial differential operators with non negative characteristic form of first kind
Gregorio Chinni, Makhlouf Derridj
We study the microlocal regularity of the analytic/Gevrey vectors for the following class of second order partial differential equations \begin{align*} P(x,D) = \sum_{\ell,j=1}^{n}…
On the microlocal regularity of the analytic vectors for "sums of squares" of vector fields
Gregorio Chinni, Makhlouf Derridj
We prove via FBI-transform a result concerning the microlocal Gevrey regularity of analytic vectors for operators sums of squares of vector fields with real-valued real analytic co…
Subelliptic estimates for some systems of complex vector fields : quasihomogeneous case
Makhlouf Derridj, Bernard Helffer
For about twenty five years it was a kind of folk theorem that complex vector-fields defined on (with open set in ) by $$ L_j = \frac{\partia…
Hypoellipticity and loss of derivatives with Appendix Analyticity and loss of derivatives
Joseph J. Kohn, Makhlouf Derridj, David S. Tartakoff
For each value of k, two complex vector fields satisfying the bracket condition are exhibited the sum of whose squares is hypoelliptic but not subelliptic - in fact the operator lo…
Analyticity and loss of derivatives
Makhlouf Derridj, David S. Tartakoff
We prove local real analytic hypoellipticity for a sum of squares of complex vector fields studied by J.J. Kohn in a paper to appear in the Annals of Mathematics entitled "Hypoelli…
Analytic Hypoellipticity for a Class of Sums of Squares of Vector Fields with Non-Symplectic Characteristic Variety
Antonio Bove, Makhlouf Derridj, David S. Tartakoff
The recent example of Hanges: in is analytic hypoelliptic in the sense of germs but not in the strong sense in any neighborhoo…