Vesa Halava - UTU Research Portal

Vesa Halava

- Professor,
Mathematics (Department of Mathematics and Statistics)

vesa.halava@utu.fi

+358 29 450 4304

+358 50 320 6267

Vesilinnantie 5

Turku

Office: 368

Contact by email.

ORCID identifier: https://orcid.org/0000-0003-3633-4902

My webpage

Areas of expertise

computability; automata and formal languages; logic; combinatorics on words

Biography

I am a Professor of Discrete Mathematics and Theoretical Computer Science.

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.

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.

Publications

3 of 4

ON THE NUMBER OF SQUARES IN PARTIAL WORDS (2010)
- RAIRO: Informatique Théorique et Applications / RAIRO: Theoretical Informatics and Applications
Harju Tero, Halava Vesa, Kärki Tomi
(A1 Refereed original research article in a scientific journal)
On the Periodicity of Morphic Words (2010)
- Lecture Notes in Computer Science
Harju, Tero; Halava, Vesa; Kärki, Tomi; Rigo, Michel
(A4 Refereed article in a conference publication )
On post correspondence problem for letter monotonic languages (2009)
- Theoretical Computer Science
Halava V, Kari J, Matiyasevich Y
(A1 Refereed original research article in a scientific journal)
Overlap-freeness in infinite partial words (2009)
- Theoretical Computer Science
Halava V, Harju T, Karki T, Seebold P
(A1 Refereed original research article in a scientific journal)
Reachability problems (RP 2008) - Preface (2009)
- International Journal of Foundations of Computer Science
Halava V, Potapov I
(C2 Editorial work for a scientific compilation book)
The theorem of Fine and Wilf for relational periods (2009)
- RAIRO: Informatique Théorique et Applications / RAIRO: Theoretical Informatics and Applications
Halava V, Harju T, Karki T
(A1 Refereed original research article in a scientific journal)
Defect theorems with compatibility relations (2008)
- Semigroup Forum
Halava V, Harju T, Kärki T
(A1 Refereed original research article in a scientific journal)
Interaction properties of relational periods (2008)
- Discrete Mathematics and Theoretical Computer Science
Halava V, Harju T, Karki T
(A1 Refereed original research article in a scientific journal)
MATRIX EQUATIONS AND HILBERT'S TENTH PROBLEM (2008)
- International Journal of Algebra and Computation
Bell P, Halava V, Harju T, Karhumaki J, Potapov I
(A1 Refereed original research article in a scientific journal)
Post Correspondence Problem for short words (2008)
- Information Processing Letters
Halava V, Harju T, Hirvensalo M, Karhumaki J
(A1 Refereed original research article in a scientific journal)
Reachability probelms (RP 2007) - Preface (2008)
- International Journal of Foundations of Computer Science
Halava V, Potapov I
(C2 Editorial work for a scientific compilation book)
Square-free partial words (2008)
- Information Processing Letters
Halava Vesa, Harju Tero, Kärki Tomi
(A1 Refereed original research article in a scientific journal)
Extension of the decidability of the marked PCP to instances with unique blocks (2007)
- Theoretical Computer Science
Halava V, Harju T, Karhumaki J, Latteux M
(A1 Refereed original research article in a scientific journal)
Improved matrix pair undecidability results (2007)
- Acta Informatica
Halava V, Hirvensalo M
(A1 Refereed original research article in a scientific journal)
On Markov's undecidability theorem for integer matrices (2007)
- Semigroup Forum
Halava V, Harju T
(A1 Refereed original research article in a scientific journal)
Relational codes of words (2007)
- Theoretical Computer Science
Halava V, Harju T, Karki T
(A1 Refereed original research article in a scientific journal)
The structure of infinite solutions of marked and binary post correspondence problems (2007)
- Theory of Computing Systems
Halava V, Harju T, Karhumaki J
(A1 Refereed original research article in a scientific journal)
Undecidability bounds for integer matrices using claus instances (2007)
- International Journal of Foundations of Computer Science
Halava V, Harju T, Hirvensalo M
(A1 Refereed original research article in a scientific journal)
Positivity of second order linear recurrent sequences (2006)
- Discrete Applied Mathematics
Halava V, Harju T, Hirvensalo M
(A1 Refereed original research article in a scientific journal)
Undecidability in omega-regular languages (2006)
- Fundamenta Informaticae
Halava V, Harju T, Karhumaki J
(A1 Refereed original research article in a scientific journal)