Zobrazeno 1 - 10
of 113
pro vyhledávání: '"Cicogna, Giampaolo"'
Autor:
Cicogna, Giampaolo
Publikováno v:
Math. Meth. Appl. Sci. (ICNAAM Proc.), vol. 36 (2013)
The strict connection between Lie point-symmetries of a dynamical system and its constants of motion is discussed and emphasized, through old and new results. It is shown in particular how the knowledge of a symmetry of a dynamical system can allow t
Externí odkaz:
http://arxiv.org/abs/1307.1983
Autor:
Cicogna, Giampaolo
Publikováno v:
Math. Meth. Appl. Sci. (ICNAAM Proc.) 37, (2014) 1819-1827
This paper describes the notion of \sigma -symmetry, which extends the one of \lambda-symmetry, and its application to reduction procedures of systems of ordinary differential equations and of dynamical systems as well. We also consider orbital symme
Externí odkaz:
http://arxiv.org/abs/1307.1986
Autor:
Cicogna, Giampaolo
Publikováno v:
Nonlinear Dynamics, vol. 67, 2909-2912 (2008)
This short note completes the symmetry analysis of a class of quasi-linear partial differential equations considered in the previous paper (Nonlinear Dynamics, Vol. 51, 309-316 (2008)): it deals with the presence of an "exceptional" Lie point symmetr
Externí odkaz:
http://arxiv.org/abs/1306.5869
Publikováno v:
Journal of Physics A 46 (2013), 235204
A deformation of the standard prolongation operation, defined on sets of vector fields in involution rather than on single ones, was recently introduced and christened "\sigma-prolongation"; correspondingly one has "\sigma-symmetries" of differential
Externí odkaz:
http://arxiv.org/abs/1305.6331
Publikováno v:
J. Phys. A 45 (2012), 355205 (29pp)
We consider a deformation of the prolongation operation, defined on sets of vector fields and involving a mutual interaction in the definition of prolonged ones. This maintains the "invariants by differentiation" property, and can hence be used to re
Externí odkaz:
http://arxiv.org/abs/1210.3647
Publikováno v:
J Lie Theory 23 (2013), 357-381
We review the notion of reducibility and we introduce and discuss the notion of orbital reducibility for autonomous ordinary differential equations of first order. The relation between (orbital) reducibility and (orbital) symmetry is investigated and
Externí odkaz:
http://arxiv.org/abs/1210.3286
Autor:
Cicogna, Giampaolo
After a brief survey of the definition and the properties of Lambda-symmetries in the general context of dynamical systems, the notion of "Lambda-constant of motion'' for Hamiltonian equations is introduced. If the Hamiltonian problem is derived from
Externí odkaz:
http://arxiv.org/abs/1102.3269
Autor:
Cicogna, Giampaolo
Publikováno v:
Proc. Inst. Math. N.A.S. Ukr., vol. 50, 77-84 (2004)
A discussion is presented, within a simple unifying scheme, about different types of symmetry of PDE's, with the introduction and a precise characterization of the notions of "standard" and "weak" conditional symmetries, together with their relations
Externí odkaz:
http://arxiv.org/abs/1012.1935
Publikováno v:
Phys. of Plasmas, 17 102506-1/8 (2010)
We discuss a new family of solutions of the Grad--Shafranov (GS) equation that describe D-shaped toroidal plasma equilibria with sharp gradients at the plasma edge. These solutions have been derived by exploiting the continuous Lie symmetry propertie
Externí odkaz:
http://arxiv.org/abs/1012.1460
Autor:
Cicogna, Giampaolo
Publikováno v:
J. Nonlin. Math. Phys., Vol. 19 (2009), 43--60
We consider symmetries and perturbed symmetries of canonical Hamiltonian equations of motion. Specifically we consider the case in which the Hamiltonian equations exhibit a Lambda symmetry under some Lie point vector field. After a brief survey of th
Externí odkaz:
http://arxiv.org/abs/1004.0300