Dipartimento di Matematica "Ulisse Dini"

Il giorno venerdi' 20 Novembre 2009 , alle ore 14,30

presso la Sala Conferenze 'F. Tricerri' del Dipartimento di Matematica 'U. Dini'

il Kazuhiro Ishige
(Tohoku University)

terra' un seminario dal titolo:

CONVEXITY BREAKING OF THE FREE BOUNDARY FOR POROUS MEDIUM EQUATIONS

Il giorno martedi' 24 Novembre 2009 , alle ore 15.00

presso la Sala Conferenze 'F. Tricerri' del Dipartimento di Matematica 'U. Dini'

il Prof. Rida Farouki
(Università di Davis, California)

terra' un seminario dal titolo:

Spatial Pythagorean hodographs, quaternions, and rotations in R^3 and R^4

Abstract
Quaternions, the first example of a non-commutative algebra, arose as a by-product of Hamilton's failed attempt to construct an "algebra of triples". Hamilton envisaged the quaternions as the "new language" of science and technology, but their place was usurped by vector analysis, an algebraically crude and overtly pragmatic subset of the quaternion algebra. A simple quaternion expression automatically generates Pythagorean quartuples of polynomials, thus yielding an elegant rotation invariant characterization of Pythagorean hodographs in R^3. Quaternions provide compact and intuitive descriptions for rotations in R^3, a fact that has lead to a renewed interest in them for robotics, computer graphics, animation, and related fields. Quaternions also describe rotations in R^4, whose strange properties provide a cautionary tale against extrapolating our geometric intuition from R^2 and R^3 to Euclidean spaces of higher dimension.

È disponibile una pagina con la programmazione dei prossimi Seminari di Analisi. I seminari si tengono di norma nella Sala Conferenze "Franco Tricerri" del Dipartimento di Matematica "Ulisse Dini" (Viale Morgagni 67/A) alle ore 14:30 del venerdì.