arXiv subjects

Ana Anušić

Publications and source records attributed to Ana Anušić.

10 recordsLinked to original sources

arXiv2025

Euclidean-type algorithm for functions with same or similar origin

Maps $f,g\colon X\to X$ are called kin if they are forward iterates of the same map $φ\colon X\to X$, up to a composition with a commuting homeomorphism. Kin form an important class of commuting maps on $X$. In this paper, we characterize kin, and give an Euclidean-type algorithm which tests when two maps $f,g\colon X\to X$ are kin. Furthermore, we compute the topological entropy of diagonal maps induced by commuting diagonal kin diagrams.

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arXiv2024

Accessibility of countable sets in plane embeddings of arc-like continua

We consider the problem of finding embeddings of arc-like continua in the plane for which each point in a given subset is accessible. We establish that, under certain conditions on an inverse system of arcs, there exists a plane embedding of the inverse limit for which each point of a given countable set is accessible. As an application, we show that for any Knaster continuum $K$, and any countable collection $\mathcal{C}$ of composants of $K$, there exists a plane embedding of $K$ in which every point in the union of the composants in $\mathcal{C}$ is accessible. We also exhibit new embeddings of the Knaster buckethandle continuum $K$ in the plane which are attractors of plane homeomorphisms, and for which the restriction of the plane homeomorphism to the attractor is conjugate to a power of the standard shift map on $K$.

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arXiv2024

The Nadler-Quinn problem on accessible points of arc-like continua

We show that if $X$ is an arc-like continuum, then for every point $x \in X$ there is a plane embedding of $X$ in which $x$ is an accessible point. This answers a question posed by Nadler in 1972, which has become known as the Nadler-Quinn problem in continuum theory. Towards this end, we develop the theories of truncations and contour factorizations of interval maps. As a corollary, we answer a question of Mayer from 1982 about inequivalent plane embeddings of indecomposable arc-like continua.

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arXiv2023

Radial departures and plane embeddings of arc-like continua

We study the problem of Nadler and Quinn from 1972, which asks whether, given an arc-like continuum $X$ and a point $x \in X$, there exists an embedding of $X$ in $\mathbb{R}^2$ for which $x$ is an accessible point. We develop the notion of a radial departure of a map $f \colon [-1,1] \to [-1,1]$, and establish a simple criterion in terms of the bonding maps in an inverse system on intervals to show that there is an embedding of the inverse limit for which a given point is accessible. Using this criterion, we give a partial affirmative answer to the problem of Nadler and Quinn, under some technical assumptions on the bonding maps of the inverse system.

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arXiv2023

The Nadler-Quinn problem for simplicial inverse systems

We show that if $X$ is an arc-like continuum which can be represented as an inverse limit of a simplicial inverse system on arcs, then for every point $x \in X$ there is a plane embedding of $X$ in which $x$ is accessible. This answers a special case of the Nadler-Quinn question from 1972.

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arXiv2020

Planar embeddings of Minc's continuum and generalizations

We show that if $f\colon I\to I$ is piecewise monotone, post-critically finite, and locally eventually onto, then for every point $x\in X=\underleftarrow{\lim}(I,f)$ there exists a planar embedding of $X$ such that $x$ is accessible. In particular, every point $x$ in Minc's continuum $X_M$ from [Question 19 p. 335 in Continuum theory : proceedings of the special session in honor of Professor Sam B. Nadler, Jr.'s 60th birthday, Lecture notes in pure and applied mathematics; v. 230, New York: Marcel Dekker.] can be embedded accessibly. All constructed embeddings are thin, i.e. can be covered by an arbitrary small chain of open sets which are connected in the plane.

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arXiv2020

Inhomogeneities in chainable continua

We study a class of chainable continua which contains, among others, all inverse limit spaces generated by a single interval bonding map which is piecewise monotone and locally eventually onto. Such spaces are realized as attractors of non-hyperbolic surface homeomorphisms. Using dynamical properties of the bonding map, we give conditions for existence of endpoints, characterize the set of local inhomogeneities, and determine when it consists only of endpoints. As a side product we also obtain a characterization of arcs as inverse limits for piecewise monotone bonding maps, which is interesting in its own right.

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arXiv2019

Planar embeddings of chainable continua

We prove that for a chainable continuum $X$ and every non-zigzag $x\in X$ there exists a planar embedding $ϕ:X\to ϕ(X)\subset\mathbb R^2$ such that $ϕ(x)$ is accessible, partially answering the question of Nadler and Quinn from 1972. Two embeddings $ϕ,ψ:X \to \mathbb R^2$ are called strongly equivalent if $ϕ\circ ψ^{-1}: ψ(X) \to ϕ(X)$ can be extended to a homeomorphism of $\mathbb R^2$. We also prove that every indecomposable chainable continuum can be embedded in the plane in uncountably many strongly non-equivalent ways.

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arXiv2019

Topological properties of Lorenz maps derived from unimodal maps

A symmetric Lorenz map is obtain by ``flipping'' one of the two branches of a symmetric unimodal map. We use this to derive a Sharkovsky-like theorem for symmetric Lorenz maps, and also to find cases where the unimodal map restricted to the critical omega-limit set is conjugate to a Sturmian shift. This has connections with properties of unimodal inverse limit spaces embedded as attractors of some planar homeomorphisms.

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arXiv2019

Folding points of unimodal inverse limit spaces

We study the properties of folding points and endpoints of unimodal inverse limit spaces. We distinguish between non-end folding points and three types of end-points (flat, spiral and nasty) and give conditions for their existence and prevalence. Additionally, we give a characterisation of tent inverse limit spaces for which the set of folding points equals the set of endpoints.

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