scholarly journals Maximal entropy measures of diffeomorphisms of circle fiber bundles

2020 ◽  
Author(s):  
Raúl Ures ◽  
Marcelo Viana ◽  
Jiagang Yang
Keyword(s):  
Fiber Bundles ◽  
Maximal Entropy ◽  
Entropy Measures

Maximal entropy measures for certain partially hyperbolic, derived from Anosov systems

2011 ◽  
Vol 32 (1) ◽  
pp. 63-79 ◽  
Author(s):  
J. BUZZI ◽  
T. FISHER ◽  
M. SAMBARINO ◽  
C. VÁSQUEZ
Keyword(s):  
Hopf Bifurcation ◽  
Maximal Entropy ◽  
Open Set ◽  
Entropy Measures ◽  
Unique Measure ◽  
Anosov Systems ◽  
Anosov System ◽  
Partially Hyperbolic ◽  
Structurally Stable ◽  
Measure Of Maximal Entropy

AbstractWe show that a class of robustly transitive diffeomorphisms originally described by Mañé are intrinsically ergodic. More precisely, we obtain an open set of diffeomorphisms which fail to be uniformly hyperbolic and structurally stable, but nevertheless have the following stability with respect to their entropy. Their topological entropy is constant and they each have a unique measure of maximal entropy with respect to which periodic orbits are equidistributed. Moreover, equipped with their respective measure of maximal entropy, these diffeomorphisms are pairwise isomorphic. We show that the method applies to several classes of systems which are similarly derived from Anosov, i.e. produced by an isotopy from an Anosov system, namely, a mixed Mañé example and one obtained through a Hopf bifurcation.

scholarly journals Discontinuity of topological entropy for Lozi maps

2011 ◽  
Vol 32 (5) ◽  
pp. 1783-1800 ◽  
Author(s):  
IZZET BURAK YILDIZ
Keyword(s):  
Topological Entropy ◽  
Small Neighborhood ◽  
Maximal Entropy ◽  
Affine Surface ◽  
Piecewise Affine ◽  
Lower Semi ◽  
Entropy Measures ◽  
Compact Case ◽  
Surface Homeomorphisms ◽  
Lozi Maps

AbstractRecently, Buzzi [Maximal entropy measures for piecewise affine surface homeomorphisms. Ergod. Th. & Dynam. Sys.29 (2009), 1723–1763] showed in the compact case that the entropy map f→htop(f) is lower semi-continuous for all piecewise affine surface homeomorphisms. We prove that topological entropy for Lozi maps can jump from zero to a value above 0.1203 as one crosses a particular parameter and hence it is not upper semi-continuous in general. Moreover, our results can be extended to a small neighborhood of this parameter showing the jump in the entropy occurs along a line segment in the parameter space.

Maximizing entropy measures for random dynamical systems

2016 ◽  
Vol 17 (05) ◽  
pp. 1750032
Author(s):  
Rafael A. Bilbao ◽  
Krerley Oliveira
Keyword(s):  
Dynamical Systems ◽  
Topological Degree ◽  
Integral Formula ◽  
Ergodic Measure ◽  
Random Dynamical Systems ◽  
Maximal Entropy ◽  
Local Diffeomorphism ◽  
Maximizing Measure ◽  
Entropy Measures ◽  
Uniform Expansion

We prove the existence of relative maximal entropy measures for certain random dynamical systems of the type [Formula: see text], where [Formula: see text] is an invertibe map preserving an ergodic measure [Formula: see text] and [Formula: see text] is a local diffeomorphism of a compact Riemannian manifold exhibiting some non-uniform expansion. As a consequence of our proofs, we obtain an integral formula for the relative topological entropy as the integral of the logarithm of the topological degree of [Formula: see text] with respect to [Formula: see text]. When [Formula: see text] is topologically exact and the supremum of the topological degree of [Formula: see text] is finite, the maximizing measure is unique and positive on open sets.

Maximal entropy measures in dimension zero

2012 ◽  
Vol 127 (1) ◽  
pp. 55-66
Author(s):  
Dawid Huczek
Keyword(s):  
Maximal Entropy ◽  
Dimension Zero ◽  
Entropy Measures

scholarly journals Maximal entropy measures for piecewise affine surface homeomorphisms

2009 ◽  
Vol 29 (6) ◽  
pp. 1723-1763 ◽  
Author(s):  
JÉRÔME BUZZI
Keyword(s):  
Periodic Points ◽  
Point Of View ◽  
Maximal Entropy ◽  
Probability Measures ◽  
Affine Surface ◽  
Piecewise Affine ◽  
Surface Diffeomorphisms ◽  
Positive Topological Entropy ◽  
Entropy Measures ◽  
Surface Homeomorphisms

AbstractWe study the dynamics of piecewise affine surface homeomorphisms from the point of view of their entropy. Under the assumption of positive topological entropy, we establish the existence of finitely many ergodic and invariant probability measures maximizing entropy and prove a multiplicative lower bound for the number of periodic points. This is intended as a step towards the understanding of surface diffeomorphisms. We proceed by building a jump transformation, using not first returns but carefully selected ‘good’ returns to dispense with Markov partitions. We control these good returns through some entropy and ergodic arguments.

Dupuytren's Contracture and Microvessels

1981 ◽  
Vol 39 ◽  
pp. 470-471
Author(s):  
C. W. Klscher ◽  
D. Speer
Keyword(s):  
Hypertrophic Scar ◽  
Active Form ◽  
Scar Tissue ◽  
Vascular Supply ◽  
Fiber Bundles ◽  
Dupuytren’S Contracture ◽  
Palmar Fascia ◽  
Immune Disease ◽  
Dupuytren's Contracture ◽  
Longitudinal Fiber

Dupuytren's Contracture is a nodular proliferation of the longitudinal fiber bundles of palmar fascia with its attendant contraction. The factors attributed to its etiology have included trauma, diabetes, alcoholism, arthritis, and auto-immune disease. The tissue has been observed by electron microscopy and found to contain myofibroblasts.Dupuytren's Contracture constitutes a scar, and as such, excessive collagen can be observed, along with an active form of fibroblast.Previous studies of the hypertrophic scar have led us to propose that integral in the initiation and sustenance of scar tissue is a profusion of microvascular regeneration, much of which becomes and remains occluded producing a hypoxia which stimulates fibroblast synthesis. Thus, when considering a study of Dupuytren's Contracture, we predicted finding occluded microvessels at or near the fascial scarring focus.Three cases of Dupuytren's Contracture yielded similar specimens, which were fixed in Karnovskys fluid for 2 to 20 days. Upon removal of the contracture bands care was taken to include the contiguous fatty and areolar tissue which contain the vascular supply and to identify the junctional area between old and new fascia.

Ultrastructural Features of the Oral Apparatus of Stentor

1976 ◽  
Vol 34 ◽  
pp. 142-143
Author(s):  
Elizabeth F. Howell
Keyword(s):  
Plasma Membrane ◽  
Osmium Tetroxide ◽  
Buccal Cavity ◽  
Fiber Bundles ◽  
Microtubular Root ◽  
Stentor Coeruleus ◽  
Root Fiber

The ultrastructure of the normal oral apparatus of Stentor has not been extensively studied. I report here on the ultrastructure of the buccal cavity of Stentor coeruleus.Stentor coeruleus was fixed in either a buffered mixture of osmium tetroxide and glutaraldehyde, or in buffered glutaraldehyde alone. Cells were then dehydrated and embedded in a mixture of Epon and Araldite.An extensive adoral zone of membranelles surrounds the anterior of the cell, and each membranelle consists of 2 parallel rows of cilia. These extend down into the buccal cavity. Two microtubular root fibers, or nemadesmata (Figs. 2 and 5), extend deeply into the cytoplasm from the base of each ciliary kinetosome. Mitochondria are usually closely associated with the root fiber bundles, and small vesicles are present between the nemadesmata of adjacent kinetosomes (Fig. 5). In the cytopharyngeal, non-ciliated areas of the buccal cavity, microtubular ribbons which extend into the cytoplasm are aligned perpendicular to the plasma membrane of the buccal cavity (Figs. 1 and 2).

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