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Parabolic Cantor sets

Mariusz Urbański (1996)

Fundamenta Mathematicae

The notion of a parabolic Cantor set is introduced allowing in the definition of hyperbolic Cantor sets some fixed points to have derivatives of modulus one. Such difference in the assumptions is reflected in geometric properties of these Cantor sets. It turns out that if the Hausdorff dimension of this set is denoted by h, then its h-dimensional Hausdorff measure vanishes but the h-dimensional packing measure is positive and finite. This latter measure can also be dynamically characterized as the...

Pourquoi les points périodiques des homéomorphismes du plan tournent-ils autour de certains points fixes ?

Patrice Le Calvez (2008)

Annales scientifiques de l'École Normale Supérieure

Soit f un homéomorphisme du plan qui préserve l’orientation et qui a un point périodique z * de période q 2 . Nous montrons qu’il existe un point fixe z tel que le nombre d’enlacement de z * et z ne soit pas nul. En d’autres termes, le nombre de rotation de l’orbite de z * dans l’anneau 2 { z } est un élément non nul de / . Ceci donne une réponse positive à une question posée par John Franks.

Powers and alternative laws

Nicholas Ormes, Petr Vojtěchovský (2007)

Commentationes Mathematicae Universitatis Carolinae

A groupoid is alternative if it satisfies the alternative laws x ( x y ) = ( x x ) y and x ( y y ) = ( x y ) y . These laws induce four partial maps on + × + ( r , s ) ...

Rotation sets for subshifts of finite type

Krystyna Ziemian (1995)

Fundamenta Mathematicae

For a dynamical system (X,f) and a function φ : X N the rotation set is defined. The case when (X,f) is a transitive subshift of finite type and φ depends on the cylinders of length 2 is studied. Then the rotation set is a convex polyhedron. The rotation vectors of periodic points are dense in the rotation set. Every interior point of the rotation set is a rotation vector of an ergodic measure.

Currently displaying 61 – 80 of 107