| Full text | |
| Author(s): |
Barostichi, R. F.
;
Ferra, I. A.
;
Petronilho, G.
Total Authors: 3
|
| Document type: | Journal article |
| Source: | Journal of Mathematical Analysis and Applications; v. 453, n. 1, p. 104-124, SEP 1 2017. |
| Web of Science Citations: | 0 |
| Abstract | |
We start this work by recalling a class of globally hypoelliptic sublaplacians defined on the N-dimensional torus introduced by Himonas and Petronilho and we consider a new class of sublaplacians that generalizes this one and prove that it is globally [omega]-hypoelliptic if and only if the coefficients satisfy a diophantine condition involving a new concept of simultaneous approximability with exponent [omega]. Furthermore we prove that this new class is globally [omega]-hypoelliptic if and only if certain perturbations of its vector fields, by adding more derivatives with respect to other variables, are globally [omega]-hypoelliptic. We also recall the Petronilho's conjecture for the smooth hypoellipticity and present a new class of sublaplacians for which the Petronilho's conjecture holds true in the ultradifferentiable functions setup. (C) 2017 Elsevier Inc. All rights reserved. (AU) | |
| FAPESP's process: | 12/03168-7 - Geometric theory of PDE and several complex variables |
| Grantee: | Jorge Guillermo Hounie |
| Support Opportunities: | Research Projects - Thematic Grants |