Prof Nik Ruskuc
Director of Research
Professor
- Phone
- +44 (0)1334 46 3787
- nik.ruskuc@st-andrews.ac.uk
- Office
- 303 MI
- Location
- Mathematical Institute
Research areas
Combinatorial semigroup theory: generating sets for semigroups and defining semigroups by presentations (generators and defining relations); presentations for substructures and algebraic constructions;
Subsemigroups: index and rank;
Group and semigroup presentations;
Transformation semigroups: properties of finite and infinite semigroups of mappings from a set into itself;
Machine and languages (theoretical computer science) in algebra: automatic structures, decidability;
Combinatorics of permutations, words, etc: pattern classes, decidability questions in combinatorics;
Computational algebra: algorithms and packages for computing with algebraic structures.
PhD supervision
- Callum Barber
- Jung Won Cho
- Victoria Ironmonger
- Struan McCartney
- Theodor Thorbjornsen
- Zhongyi Zhou
- Yayi Zhu
Selected publications
-
Open access
Coherency properties for monoids of transformations and partitions
Brookes, M., Gould, V. & Ruskuc, N., Jan 2025, In: Mathematika. 71, 1, 14 p., e70005.Research output: Contribution to journal › Article › peer-review
-
Open access
Congruences of maximum regular subsemigroups of variants of finite full transformation semigroups
Dolinka, I., East, J. & Ruskuc, N., 15 Jan 2025, In: Journal of Algebra. 662, p. 431-464Research output: Contribution to journal › Article › peer-review
-
Open access
Graph products of residually finite monoids are residually finite
Cho, J. W., Gould, V., Ruskuc, N. & Yang, D., 15 Jan 2025, In: Journal of Algebra. 662, p. 514-527Research output: Contribution to journal › Article › peer-review
-
Open access
On the number of subdirect products involving semigroups of integers and natural numbers
Clayton, A., Reilly, C. & Ruskuc, N., 18 Feb 2025, (E-pub ahead of print) In: Journal of Algebra and Its Applications. Online ReadyResearch output: Contribution to journal › Article › peer-review
-
Open access
Projection algebras and free projection- and idempotent-generated regular ∗-semigroups
East, J., Gray, R. D., Azeef Muhammed, P. A. & Ruškuc, N., 1 Jul 2025, In: Advances in Mathematics. 473, 61 p., 110288.Research output: Contribution to journal › Article › peer-review
-
Open access
Semigroup congruences and subsemigroups of the direct square
Barber, C. & Ruškuc, N., 7 Jul 2025, (E-pub ahead of print) In: Bulletin of the Australian Mathematical Society. First View, 12 p.Research output: Contribution to journal › Article › peer-review
-
Open access
Twisted products of monoids
East, J., Gray, R. D., Muhammed, P. A. A. & Ruškuc, N., 1 Mar 2026, In: Journal of Algebra. 689, p. 819-861 43 p.Research output: Contribution to journal › Article › peer-review
-
Open access
A characterisation of semigroups with only countably many subdirect products with Z
Clayton, A. M. W., Reilly, C. & Ruskuc, N., 4 Oct 2024, (E-pub ahead of print) In: Bulletin of the Australian Mathematical Society. First View, 10 p.Research output: Contribution to journal › Article › peer-review
-
Open access
Decidability of well quasi-order and atomicity for equivalence relations under embedding orderings
Ironmonger, V. L. & Ruskuc, N., 14 Feb 2024, (E-pub ahead of print) In: Order. 26 p.Research output: Contribution to journal › Article › peer-review
-
Open access
Heights of one- and two-sided congruence lattices of semigroups
Brookes, M., East, J., Miller, C., Mitchell, J. D. & Ruskuc, N., 2024, In: Pacific Journal of Mathematics. 333, 1, p. 17-58 41 p.Research output: Contribution to journal › Article › peer-review