The dynamical laws of physics in their conventional formulation are time reversible. The description of irreversible phenomena was always thought to be incompatible with the dynamical laws. We have recently discussed [1, 2, 3, 9, 10, 11, 12] the origin of irreversible behaviour due to resonances in various Poincaré nonintegrable quantum systems. The analytic extension of the Hamiltonian or Liou...

The purpose of this article is to derive the generalized formula of relativistic phase velocity transformation, by utilizing the Lorentz transforms on the wavevector k and frequency w for the moving inertial frame relative to the static system moving uniformly in an arbitrary direction. Furthermore, some significant cases are discussed. R 6 w & Cet essai est pour dCriver le gCniralisateur formu...

Perfectly Matched Layers (PMLs) appear as a popular alternative to non-reflecting boundary conditions for wave-type problems. The core idea is extend the computational domain by fictitious layer with specific absorption properties such that wave amplitude decays significantly and does not produce back reflections. In context of convected acoustics, it well-known PMLs are exposed stability issue...

Contracting the h-deformation of SL(2, R), we construct a new deformation of two dimensional Poincaré algebra, the algebra of functions on its group and its differential structure. It is also shown that the Hopf algebra is triangular, and its universal R matrix is also constructed explicitly. Then, we find a deformation map for the universal enveloping algebra, and at the end, give the deformed...