Results 11 to 20 of about 1,579 (213)
On Kohn’s sums of squares of complex vector fields
Matemática Contemporânea, 2022 Summary: This is a survey of some recent alternative way of proving a subelliptic estimate, first proven by J. J. Kohn, for certain sums of squares of \textit{complex} vector fields. My approach here makes it possible to extend the result also to more general families of complex vector fields, to perturbations of sums of squares operators by a first ...
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Analytic Hypoellipticity and the Treves Conjecture
Bruno Pini Mathematical Analysis Seminar, 2016 We are concerned with the problem of the analytic hypoellipticity; precisely, we focus on the real analytic regularity of the solutions of sums of squares with real analytic coefficients. Treves conjecture states that an operator of this type is analytic
Marco Mughetti
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Global analytic regularity for sums of squares of vector fields [PDF]
Transactions of the American Mathematical Society, 1998 We consider a class of operators in the form of a sum of squares of vector fields with real analytic coefficients on the torus and we show that the zero order term may influence their global analytic hypoellipticity. Also we extend a result of Cordaro-Himonas.
Cordaro, Paulo D. +1 more
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Геодинамика и тектонофизика, 2017 The Bishkek geodynamic polygon (BGP, 41.5–43.5° N – 73–77° E) is located within the central segment of the North Tien Shan seismic zone, in the junction zone of the Tien Shanorogene and the Turan plate (Fig. 1).
N. A. Sycheva, A. N. Mansurov
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Some nonanalytic-hypoelliptic sums of squares of vector fields [PDF]
Bulletin of the American Mathematical Society, 1992 Certain second-order partial differential operators, which are expressed as sums of squares of real-analytic vector fields in R
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Loss of derivatives for systems of complex vector fields and sums of squares [PDF]
Proceedings of the American Mathematical Society, 2011 We discuss, both for systems of complex vector fields and for sums of squares, the phenomenon discovered by Kohn of hypoellipticity with loss of derivatives.
Khanh T. V., Pinton S., Zampieri G.
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Analytic hypoellipticity for sums of squares of vector fields [PDF]
Annales Polonici Mathematici, 1998 This paper is a synthetic, lucid and up to date review of the status of the theory concerning analytic hypoellipticity of sums of squares operators. First the author discusses the local theory; there are two famous conjectures by François Treves, that spurred quite a number of papers on the subject.
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Some advances in analytic hypoellipticity
Bruno Pini Mathematical Analysis SeminarWe present a brief survey on the theory of the real analytic regularity for the solutions to sums of squares of vector fields satisfying the Hörmander condition.
Marco Mughetti
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Global hypoellipticity for sums of squares of vector fields of infinite type.
Matemática Contemporânea, 1998 This paper deals with the global \(C^\infty\) hypoellipticity for a class of second-order differential operators on the torus. These operators are sums of squares of real-valued vector fields. A necessary and sufficient condition for global \(C^\infty\) hypoellipticity is proved.
Gerson Petronilho, A. Himonas
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Hölder-continuity of the solutions for operators which are a sum of squares of vector fields plus a potential [PDF]
Proceedings of the American Mathematical Society, 1994 In this paper we study the local Hölder-regularity of weak solutions to L u +
DI FAZIO, Giuseppe, G. CITTI
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