33,634 research outputs found
Tischler graphs of critically fixed rational maps and their applications
A rational map on the Riemann
sphere is called critically fixed if each critical point
of is fixed under . In this article we study properties of a
combinatorial invariant, called Tischler graph, associated with such a map.
More precisely, we show that the Tischler graph of a critically fixed rational
map is always connected, establishing a conjecture made by Kevin Pilgrim. We
also discuss the relevance of this result for classical open problems in
holomorphic dynamics, such as combinatorial classification problem and global
curve attractor problem
Extremal Infinite Graph Theory
We survey various aspects of infinite extremal graph theory and prove several
new results. The lead role play the parameters connectivity and degree. This
includes the end degree. Many open problems are suggested.Comment: 41 pages, 16 figure
Dynamics of McMullen maps
In this article, we develop the Yoccoz puzzle technique to study a family of
rational maps termed McMullen maps. We show that the boundary of the immediate
basin of infinity is always a Jordan curve if it is connected. This gives a
positive answer to a question of Devaney. Higher regularity of this boundary is
obtained in almost all cases. We show that the boundary is a quasi-circle if it
contains neither a parabolic point nor a recurrent critical point. For the
whole Julia set, we show that the McMullen maps have locally connected Julia
sets except in some special cases.Comment: Complex dynamics, 51 pages, 13 figure
A Combinatorial classification of postcritically fixed Newton maps
We give a combinatorial classification for the class of postcritically fixed
Newton maps of polynomials as dynamical systems. This lays the foundation for
classification results of more general classes of Newton maps.
A fundamental ingredient is the proof that for every Newton map
(postcritically finite or not) every connected component of the basin of an
attracting fixed point can be connected to through a finite chain of
such components.Comment: 37 pages, 5 figures, published in Ergodic Theory and Dynamical
Systems (2018). This is the final author file before publication. Text
overlap with earlier arxiv file observed by arxiv system relates to an
earlier version that was erroneously uploaded separately. arXiv admin note:
text overlap with arXiv:math/070117
Combinatorial models of expanding dynamical systems
We define iterated monodromy groups of more general structures than partial
self-covering. This generalization makes it possible to define a natural notion
of a combinatorial model of an expanding dynamical system. We prove that a
naturally defined "Julia set" of the generalized dynamical systems depends only
on the associated iterated monodromy group. We show then that the Julia set of
every expanding dynamical system is an inverse limit of simplicial complexes
constructed by inductive cut-and-paste rules.Comment: The new version differs substantially from the first one. Many parts
are moved to other (mostly future) papers, the main open question of the
first version is solve
Graph Signal Processing: Overview, Challenges and Applications
Research in Graph Signal Processing (GSP) aims to develop tools for
processing data defined on irregular graph domains. In this paper we first
provide an overview of core ideas in GSP and their connection to conventional
digital signal processing. We then summarize recent developments in developing
basic GSP tools, including methods for sampling, filtering or graph learning.
Next, we review progress in several application areas using GSP, including
processing and analysis of sensor network data, biological data, and
applications to image processing and machine learning. We finish by providing a
brief historical perspective to highlight how concepts recently developed in
GSP build on top of prior research in other areas.Comment: To appear, Proceedings of the IEE
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