159 citations
- Roma Tre UniversityIT19 papers
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma IIT7 papers
- Politecnico di MilanoIT7 papers
- Sapienza University of RomeIT7 papers
- University of Naples Federico IIIT7 papers
- University of Rome Tor VergataIT7 papers
- Giustino Fortunato UniversityIT6 papers
- Graz University of TechnologyAT6 papers
- Mediterranean Institute of Fundamental PhysicsIT6 papers
- Chinese Academy of SciencesCN5 papers
- Gubkin Russian State University of Oil and GasRU5 papers
- Institute of AcousticsCN4 papers
5 papers · 1 filter
The Freeness Problem for Automaton Semigroups
Daniele D'Angeli, Emanuele Rodaro, Jan Philipp Wächter
We show that the freeness problems for automaton semigroups and for automaton monoids are undecidable and, thereby, solve an open problem listed by Grigorchuk, Nekrashevych and Sus…
Infinite Automaton Semigroups and Groups Have Infinite Orbits
Daniele D'Angeli, Dominik Francoeur, Emanuele Rodaro +1
We show that an automaton group or semigroup is infinite if and only if it admits an -word (i. e. a right-infinite word) with an infinite orbit, which solves an open problem com…
Orbit Expandability of Automaton Semigroups and Groups
Daniele D'Angeli, Emanuele Rodaro, Jan Philipp Wächter
We introduce the notion of expandability in the context of automaton semigroups and groups: a word is k-expandable if one can append a suffix to it such that the size of the orbit…
On the Structure Theory of Partial Automaton Semigroups
Daniele D'Angeli, Emanuele Rodaro, Jan Philipp Wächter
We study automaton structures, i.e. groups, monoids and semigroups generated by an automaton, which, in this context, means a deterministic finite-state letter-to-letter transducer…
Automaton Semigroups and Groups: On the Undecidability of Problems Related to Freeness and Finiteness
Daniele D'Angeli, Emanuele Rodaro, Jan Philipp Wächter
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 con…