activity
20012026
most citedInfinite powers and Cohen reals

3 citations · 12 across the 17 of their papers we have counts for

collaborators

22 papers

cs.AI2026

World Potential Model: Pretrained World Knowledge as Progress Potentials

Jun Zhao, Jixin Tang, Yang Shu +6

Long-horizon language agents often receive supervision only from terminal task outcomes, leaving little signal for distinguishing productive intermediate behavior from stagnation o…

math.GN2024

-embedding, Lindelöfness, and Čech-completeness

Alan Dow, Klaas Pieter Hart, Jan van Mill +1

We show that in the class of Lindelöf Čech-complete spaces the property of being -embedded is quite well-behaved. It admits a useful characterization that can be used to show th…

math.GN2024★ 1 cited

Buried points of plane continua

David Lipham, Jan van Mill, Murat Tuncali +2

Sets on the boundary of a complementary component of a continuum in the plane have been of interest since the early 1920's. Curry and Mayer defined the buried points of a plane con…

math.GN2023

Nowhere constant families of maps and resolvability

István Juhász, Jan van Mill

If is a topological space and is any set then we call a family of maps from to nowhere constant if for every non-empty open set in there is $f…

math.GN2023

Homogeneous continuous images of smaller weight

István Juhász, Jan van Mill

We show that every infinite crowded space can be mapped onto a homogeneous space of countable weight, and that there is a homogeneous space of weight continuum that cannot be mappe…

math.LO2023

On Shehtman's Two Problems

Guram Bezhanishvili, Nick Bezhanishvili, Joel Lucero-Bryan +1

We provide partial solutions to two problems posed by Shehtman concerning the modal logic of the Čech-Stone compactification of an ordinal space. We use the Continuum Hypothesis to…

math.GN2023

Closed copies of in

Alan Dow, Klaas Pieter Hart, Jan van Mill +1

We investigate closed copies of~ in powers of~ with respect to - and -embedding. We show that contains closed copies of~$\mathbb{…

math.GN2023

On the double density spectra of compact spaces

István Juhász, Jan Van Mill

The set of densities of all dense subspaces of a topological space is called the double density spectrum of . In this note we present a couple of results that imply…

math.GN2022

Some realcompact spaces

Alan Dow, Jan van Mill, Klaas Pieter Hart +1

We present examples of realcompact spaces with closed subsets that are C*-embedded but not C-embedded, including one where the closed set is a copy of the space of natural numbers.

math.GN2022★ 3 cited

Problems on

Klaas Pieter Hart, Jan van Mill

This is an update on, and expansion of, our paper Open problems on in the book Open Problems in Topology.

math.GN2021

The double density spectrum of a topological space

Istvan Juhasz, Jan van Mill, Lajos Soukup +1

It is an interesting, maybe surprising, fact that different dense subspaces of even "nice" topological spaces can have different densities. So, our aim here is to investigate the s…

math.GN2021★ 1 cited

Universal autohomeomorphisms of

Klaas Pieter Hart, Jan van Mill

We study the existence of universal autohomeomorphisms of . We prove that implies there is such an autohomeomorphism and show that there are none in any…

math.GN2021

Conjugacy classes of autohomeomorphisms of

Klaas Pieter Hart, Jan van Mill

We present some problems related to the conjugacy classes of .

math.GN2018

Actions of semitopological groups

Jan van Mill, Vesko Valov

We investigate continuous transitive actions of semitopological groups on spaces, as well as separately continuous transitive actions of topological groups.

math.GN2018★ 2 cited

Compactifiable classes of compacta

A. Bartoš, J. Bobok, J. van Mill +2

We introduce the notion of compactifiable classes -- these are classes of metrizable compact spaces that can be up to homeomorphic copies ``disjointly combined'' into one metrizabl…

math.GN2017★ 3 cited

Infinite powers and Cohen reals

Andrea Medini, Jan van Mill, Lyubomyr Zdomskyy

We give a consistent example of a zero-dimensional separable metrizable space such that every homeomorphism of acts like a permutation of the coordinates almost everywher…

math.GN2016

Alan Dow

Klaas Pieter Hart, Jan van Mill

On the occasion of Alan Dow 60th birthday.

math.GN2014

A homogeneous space whose complement is rigid

Andrea Medini, Jan van Mill, Lyubomyr Zdomskyy

We construct a homogeneous subspace of whose complement is dense in and rigid. Using the same method, assuming Martin's Axiom, we also construct a countable dense homog…

math.GT2013

A short proof of Toruńczyk's Characterization Theorems

Jan J. Dijkstra, Michael Levin, Jan van Mill

We present short proofs of Toruńczyk's well-known characterization theorems of the Hilbert cube and Hilbert space, respectively.

math.GN2013

Unions of F-spaces

Klaas Pieter Hart, Leon Luo, Jan van Mill

We show that every space that is the union of a `small' family consisting of special P-sets that are F-spaces, is an F-space. We also comment on the sharpness of our results.

math.GN2009★ 2 cited

Covering dimension and finite-to-one maps

Klaas Pieter Hart, Jan van Mill

Hurewicz' characterized the dimension of separable metrizable spaces by means of finite-to-one maps. We investigate whether this characterization also holds in the class of compact…

math.LO2001

Embeddings into P(N)/fin and extension of automorphisms

A. Bella, A. Dow, K. P. Hart +3

Given a Boolean algebra B and an embedding e:B -> P(N)/fin we consider the possibility of extending each or some automorphism of B to the whole P(N)/fin. Among other things, we sho…