Displaying similar documents to “Contact hamiltonians distinguishing locally certain Goursat systems”

Anisotropic complex structure on the pseudo-Euclidean Hurwitz pairs

W. Królikowski (1991)

Annales Polonici Mathematici

Similarity:

The concept of supercomplex structure is introduced in the pseudo-Euclidean Hurwitz pairs and its basic algebraic and geometric properties are described, e.g. a necessary and sufficient condition for the existence of such a structure is found.

The proof of the Nirenberg-Treves conjecture

Nils Dencker (2003)

Journées équations aux dérivées partielles

Similarity:

We prove the Nirenberg-Treves conjecture : that for principal type pseudo-differential operators local solvability is equivalent to condition ( Ψ ). This condition rules out certain sign changes of the imaginary part of the principal symbol along the bicharacteristics of the real part. We obtain local solvability by proving a localizable estimate for the adjoint operator with a loss of two derivatives (compared with the elliptic case). The proof involves a new metric in the Weyl (or Beals-Fefferman)...

State-space realization of nonlinear control systems: unification and extension via pseudo-linear algebra

Juri Belikov, Ülle Kotta, Maris Tõnso (2012)

Kybernetika

Similarity:

In this paper the tools of pseudo-linear algebra are applied to the realization problem, allowing to unify the study of the continuous- and discrete-time nonlinear control systems under a single algebraic framework. The realization of nonlinear input-output equation, defined in terms of the pseudo-linear operator, in the classical state-space form is addressed by the polynomial approach in which the system is described by two polynomials from the non-commutative ring of skew polynomials....