activity
20152023
most citedDigital Fixed Points, Approximate Fixed Points, and Universal Functions

30 citations · 48 across the 28 of their papers we have counts for

collaborators

36 papers

math.GT2023

Trimming and Building Freezing Sets

Laurence Boxer

We develop new tools for the construction of fixed point sets in digital topology. We define excludable points and show that these may be excluded from all freezing sets. We show t…

math.GT2023

Remarks on Fixed Point Assertions in Digital Topology, 7

Laurence Boxer

This paper continues a series discussing flaws in published assertions concerning fixed points in digital images.

math.GT2023

Limiting Sets for Digital Cones and Suspensions

Laurence Boxer

Cone and suspension constructions have been introduced in digital topology, modeled on those of classical topology. For digital cones and suspensions, and for some related digital…

math.GT2023

Variants on Digital Covering Maps

Laurence Boxer

SE Han's paper [11] discusses several variants of digital covering maps. We show several equivalences among these variants and discuss shortcomings in Han's paper.

math.GN2023

Limiting Sets in Digital Topology

Laurence Boxer

Freezing sets and cold sets have been introduced as part of the theory of fixed points in digital topology. In this paper, we introduce a generalization of these notions, the limit…

math.GT2022

Remarks on Fixed Point Assertions in Digital Topology, 6

Laurence Boxer

This paper continues a series discussing flaws in published assertions concerning fixed points in digital metric spaces.

math.GT2022

Freezing Sets for Arbitrary Digital Dimension

Laurence Boxer

We show how to obtain freezing sets for digital images in for arbitrary , using the and adjacencies.

math.GT2022

Some Consequences of Restrictions on Digitally Continuous Functions

Laurence Boxer

We study the consequences of some restrictions on digitally continuous functions. One of our results modifies easily to yield an analogous result for topological spaces.

math.GT2021

Remarks on Fixed Point Assertions in Digital Topology, 5

Laurence Boxer

We discuss published assertions concerning fixed points in digital metric spaces that are incorrect or incorrectly proven, or reduce to triviality.

cs.CG2021

Beyond the Hausdorff Metric in Digital Topology

Laurence Boxer

Two objects may be close in the Hausdorff metric, yet have very different geometric and topological properties. We examine other methods of comparing digital images such that objec…

math.GT2021

Hyperspaces and Function Graphs in Digital Topology

Laurence Boxer

We adapt the study of hyperspaces and function spaces from classical topology to digital topology. We define digital hyperspaces and digital function graphs, and study some of thei…

math.GT2021

Cold and Freezing Sets in the Digital Plane

Laurence Boxer

Cold sets and freezing sets belong to the theory of (approximate) fixed points for continuous self-maps on digital images. We study some properties of cold sets for digital images…

math.MG2021

AFPP and Unions of Convex Disks in the Digital Plane

Laurence Boxer

We use results of [6] to enlarge our knowledge of the approximate fixed point property (AFPP) for digital images in . In particular, we study conditions under which t…

math.GT2020★ 2 cited

Convexity and AFPP in the Digital Plane

Laurence Boxer

We examine the relationship between convexity and the approximate fixed point property (AFPP) for digital images in Z^2.

math.GT2020

Subsets and Freezing Sets in the Digital Plane

Laurence Boxer

We continue the study of freezing sets for digital images introduced in [4, 2, 3]. We prove methods for obtaining freezing sets for digital images (X, c_i) for X \subset Z^2 and i…

math.GT2020

Convexity and Freezing Sets in Digital Topology

Laurence Boxer

We continue the study of freezing sets in digital topology, introduced in [2]. We show how to find a minimal freezing set for a "thick" convex disk X in the digital plane Z^2. We g…

math.GT2020★ 3 cited

Approximate Fixed Point Property for Digital Trees and Products

Laurence Boxer

We add to our knowledge of the approximate fixed point property (AFPP) in digital topology. We show that a digital image that is a tree has the AFPP. Given two digital images (X, κ…

math.GT2020

Remarks on Fixed Point Assertions in Digital Topology, 4

Laurence Boxer

We continue the work of [4, 2, 3], in which we discuss published assertions that are incorrect or incorrectly proven; that are severely limited or reduce to triviality; or that we…

math.GN2019★ 4 cited

Approximate Fixed Point Properties in Digital Topology

Laurence Boxer

We study the approximate fixed point property (AFPP) for continuous single-valued functions and for continuous multivalued functions in digital topology. We extend what is known ab…

math.GT2019

MSS_18 is Digitally 18-contractible

Laurence Boxer

The paper [10] incorrectly asserts that the digital image MSS_18, a digital model of the Euclidean 2-sphere S^2, is not 18-contractible. We show this assertion is false.

math.GT2019

Fixed Point Sets in Digital Topology, 2

Laurence Boxer

We continue the work of [10], studying properties of digital images determined by fixed point invariants. We introduce pointed versions of invariants that were introduced in [10].…

math.GN2019

Fixed point sets in digital topology, 1

Laurence Boxer, P. Christopher Staecker

In this paper, we examine some properties of the fixed point set of a digitally continuous function. The digital setting requires new methods that are not analogous to those of cla…

math.GN2018

Remarks on Fixed Point Assertions in Digital Topology, 3

Laurence Boxer

We continue the work of [5] and [3], in which are considered papers in the literature that discuss fixed point assertions in digital topology. We discuss published assertions that…

math.GT2018

Remarks on Fixed Point Assertions in Digital Topology, 2

Laurence Boxer

Several recent papers in digital topology have sought to obtain fixed point results by mimicking the use of tools from classical topology, such as complete metric spaces. We show t…