Vesa
Halava
Professor, Mathematics
Links
Areas of expertise
computability
automata and formal languages
logic
combinatorics on words
Biography
I am a Professor of Discrete Mathematics and Theoretical Computer Science.
Teaching
I teach two course in Logic, basic course and advanced level course. I also teach Analysis I for (the first year) students of mathematics.
Research
My main field of research is in the field of Computability, more precisely on undecidable problems in automata and formal langauges and in the semigroups generated by integer matrices. Recently, I have also focused on the Foundations of Computation and related issues in the Foundations of Mathematics -- in Logic and Set Theory. I have also published articles in Combinatorics on Words.
Publications
Certain linear and weakly linear systems of matrix equations over semirings. Applications in a state reduction of weighted automata (2022)
Filomat
(Vertaisarvioitu alkuperäisartikkeli tai data-artikkeli tieteellisessä aikakauslehdessä (A1))
Integer Weighted Automata on Infinite Words (2022)
International Journal of Foundations of Computer Science
(Vertaisarvioitu alkuperäisartikkeli tai data-artikkeli tieteellisessä aikakauslehdessä (A1))
Undecidability in Finite Transducers, Defense Systems and Finite Substitutions (2021)
arXiv.org
(Muu (O2))
Integer Weighted Automata on Infinite Words (2021)
International Conference on Developments in Language Theory, Lecture Notes in Computer Science
(Vertaisarvioitu artikkeli konferenssijulkaisussa (A4))
On the Steps of Emil Post: from Normal Systems to the Correspondence Decision Problem (2020)
Acta Cybernetica
(Vertaisarvioitu alkuperäisartikkeli tai data-artikkeli tieteellisessä aikakauslehdessä (A1))
On Shuffling a Word with its Letter-to-Letter Substitution (2020)
Fundamenta Informaticae
(Vertaisarvioitu alkuperäisartikkeli tai data-artikkeli tieteellisessä aikakauslehdessä (A1))
On fixed points of rational transductions (2018)
Theoretical Computer Science
(Vertaisarvioitu alkuperäisartikkeli tai data-artikkeli tieteellisessä aikakauslehdessä (A1))
Preface -- Russian-Finnish Symposium in Discrete Mathematics (Fundamenta Informaticae, vol. 162, no. 2-3, pp. i-i, 2018) (2018)
Fundamenta Informaticae
(Muu (O2))
A new proof for undecidability of the bi-infinite post correspondence problem (2017)
Fundamenta Informaticae
(Vertaisarvioitu alkuperäisartikkeli tai data-artikkeli tieteellisessä aikakauslehdessä (A1))