Automaton semigroups and groups: on the undecidability of problems related to freeness and finiteness

D D'Angeli, E Rodaro, JP Wächter - Israel Journal of Mathematics, 2020 - Springer
In this paper, we study algorithmic problems for automaton semigroups and automaton
groups related to freeness and finiteness. In the course of this study, we also exhibit some …

[HTML][HTML] On the complexity of the word problem for automaton semigroups and automaton groups

D D'Angeli, E Rodaro, JP Wächter - Advances in Applied Mathematics, 2017 - Elsevier
In this paper, we study the word problem for automaton semigroups and automaton groups
from a complexity point of view. As an intermediate concept between automaton semigroups …

The Lamplighter Group ℤ3≀ℤ Generated by a Bireversible Automaton

I Bondarenko, D D'Angeli, E Rodaro - Communications in Algebra, 2016 - Taylor & Francis
Full article: The Lamplighter Group ℤ3≀ℤ Generated by a Bireversible Automaton Skip to Main
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Automaton semigroups: The two-state case

I Klimann - Theory of Computing Systems, 2016 - Springer
We prove that semigroups generated by reversible two-state Mealy automata have
remarkable growth properties: they are either finite or free. We give an effective procedure to …

[HTML][HTML] Freeness of automaton groups vs boundary dynamics

D D'Angeli, E Rodaro - Journal of Algebra, 2016 - Elsevier
We prove that the boundary dynamics of the (semi) group generated by the enriched dual
transducer characterizes the algebraic property of being free for an automaton group. We …

A geometric approach to (semi)-groups defined by automata via dual transducers

D D'Angeli, E Rodaro - Geometriae Dedicata, 2015 - Springer
We give a geometric approach to groups defined by automata via the notion of enriched
dual of an inverse transducer. Using this geometric correspondence we first provide some …

Boundary action of automaton groups without singular points and Wang tilings

D D'Angeli, T Godin, I Klimann, M Picantin… - arxiv preprint arxiv …, 2016 - arxiv.org
We study automaton groups without singular points, that is, points in the boundary for which
the map that associates to each point its stabilizer, is not continuous. This is motivated by the …

Boundary dynamics for bireversible and for contracting automaton groups

D D'Angeli, T Godin, I Klimann, M Picantin… - International Journal of …, 2020 - World Scientific
We study the dynamics of the action of an automaton group on the set of infinite words, and
more precisely the discontinuous points of the map which associates to a point its set of …

Fragile words and Cayley type transducers

D D'Angeli, E Rodaro - International journal of group theory, 2018 - re.public.polimi.it
We address the problem of finding examples of non-bireversible transducers defining free
groups, we show examples of transducers with sink accessible from every state which …

[PDF][PDF] Schreier graphs of an extended version of the binary adding machine

D D'Angeli - The Electronic Journal of Combinatorics, 2014 - combinatorics.org
Schreier graphs of an extended version of the binary adding machine Page 1 Schreier
graphs of an extended version of the binary adding machine Daniele D’Angeli ∗ Institut für …