Publications and Preprints

If you wish to receive a copy of any of these articles -- please send me an email, and I'd be happy to provide a (signed, personalised) copy!

Publications (newest first):

1. C.-F. Nyberg-Brodda, "On the Dehn functions of a class of monadic one-relation monoids", C. Rendus Mathématique (accepted, 2023).

2. M. Pichler, A. Meindl, M. Romberger, A. Eckes-Shepard, C.-F. Nyberg-Brodda, C. Buhigas, S. Llaneza-Lago, G. Lehmann, A. Hopes, G. Meister, J. Medenbach, T. Mock, "Ribosome profiling in the model diatom Thalassiosira pseudonana", Current Protocols (accepted, 2023), doi:101002/cpz1.843.

3. C.-F. Nyberg-Brodda, "On the word problem for weakly compressible monoids", Communications in Algebra (accepted, 2023)

4. C.-F. Nyberg-Brodda, "On the word problem for free products of semigroups and monoids", Journal of Algebra 622, (2023), pp. 721-741.

5. C.-F. Nyberg-Brodda, "A word-hyperbolic special monoid with undecidable Diophantine problem", Israel J. of Mathematics (accepted).

6. C.-F. Nyberg-Brodda, "Multiplication tables and word-hyperbolicity in free products of semigroups, monoids, and groups", J. AustMath. Soc. (accepted).

7. C.-F. Nyberg-Brodda, "Non-finitely generated maximal subgroups of context-free monoids", Journal of Algebra 616, (2023), pp. 227-238.

8. C.-F. Nyberg-Brodda, "On one-relator groups and units of special one-relation inverse monoids", Int. J. of Alg. and Comp. 32:7, (2022). pp.1379-1401.

9. C.-F. Nyberg-Brodda, "On the word problem for special monoids", Semigroup Forum 105:1, (2022), pp. 295-327. 

10. C.-F. Nyberg-Brodda, "The word problem for one-relation monoids: a survey", Semigroup Forum 103:2, (2021), pp. 297–355.

11. C.-F. Nyberg-Brodda, "The B. B. Newman Spelling Theorem", British J. for the History of Mathematics 36:2, (2021), pp. 117-131.

Preprints (newest first):

1. V. Berthé, H. Goulet-Ouellet, C.-F. Nyberg-Brodda, D. Perrin, K. Petersen, Density of group languages in shift spaces, 2024, arXiv:2403.17892

2. C.-F. Nyberg-Brodda, "G. S. Tseytin's seven-relation semigroup with undecidable word problem", 2024, arXiv:2401.11757

3. C.-F. Nyberg-Brodda, "The abelianization of SL2(ℤ[1/p])", 2024, arXiv:2401.08146

4. C.-F. Nyberg-Brodda, "On congruence subgroups of SL2(ℤ[1/p]) generated by two parabolic elements", 2023, arXiv:2312.11258.

5. I. Foniqi, R. D. Gray & C.-F. Nyberg-Brodda, "Membership problems for positive one-relator groups and one-relation monoids", 2023, arXiv:2305.15672

6. C.-F. Nyberg-Brodda, "Tropical one-relation monoids", (2022), arxiv:2209.12612.

7. C.-F. Nyberg-Brodda, "On the Diophantine problem in some one-relator groups", (2022), arXiv:2208.07145.

8. C.-F. Nyberg-Brodda, "The Geometry of Special Monoids", (2020), arXiv:2011.04536.

Translations and Miscellaneous Work

I sometimes do English translations of old (primarily Russian) articles! If you have something you want translated, let me know.
Some articles are without links for copyright reasons. If you wish to receive a copy, drop me a line and I'll send you a pdf (non-commercial use only).

Note: I am an official translator (Russian to English) for the Transactions of the Moscow Mathematical Society. The translation is organised jointly by the London Mathematical Society and the American Mathematical Society. My work in this capacity does not constitute endorsement of the policies or actions of any government or other agencies. In particular, I condemn the barbaric 2022 Russian invasion of Ukraine in the strongest possible terms.

• Six Ukrainian articles on semigroup theory by A. K. Sushkevich (2023), arXiv:2203.02996.
  This translation was featured on the website of the Ukrainian Mathematical Community.
  It contains a translation of six separate articles, originally written in Ukrainian:

  • A. K. Sushkevich, "On extending a semigroup to a whole group", Scientific Notes of the Kharkiv Mathematical Society, 4:12 (1935), pp. 81–87.

  • A. K. Sushkevich, "On some properties of a type of generalised groups", Scientific Notes of the Kharkiv State University, 2–3 (1935), pp. 23–25.

  • A. K. Sushkevich, "Investigations in the field of generalised groups", Scientific Notes of the Kharkiv State University, 6–7 (1936), pp. 49–52.

  • A. K. Sushkevich, "On groups of matrices of rank 1", J. Inst. Math. Akad. Nauk UkrSSR, 3 (1937), pp. 83–94.

  • A. K. Sushkevich, "On some types of singular matrices", Scientific Notes of the Kharkiv State University, 10 (1951), pp. 5–16.

  • A. K. Sushkevich, "Generalised groups of some types of infinite matrices", Note. Sci. Res. Inst. Khar. S. Univ. & Khar. M. Soc 16 (1939), pp. 115–120
    
    

• The Adian--Rabin Theorem -- an English Translation, (2022), arXiv:2208.08560.
  This contains a translation of six separate articles, originally written in Russian:

  • A. A. Markov, "Impossibility of some algorithms in the theory of associative systems", Dokl. Akad. Nauk SSSR, 77:1, (1951), pp. 19-20.

  • A. A. Markov, "Impossibility of algorithms for recognising some properties of associative systems", Dokl. Akad. Nauk SSSR, 77:6, 1951, pp. 953-956.

  • S. I. Adian, "Algorithmic unsolvability of problems of recognition of certain properties of groups", Dokl. Akad. Nauk SSSR, 103:4 (1955), pp. 533-535.

  • S. I. Adian, "Unsolvability of some algorithmic problems in the theory of groups", Proc. Moscow Math. Soc. 6, (1957), pp. 231-298.

  • S. I. Adian, "Finitely presented groups and algorithms", Dokl. Akad. Nauk SSSR, 117:1, (1957), pp. 9-12.

  • S. I. Adian, "On algorithmic problems in effectively complete classes of groups", Dokl. Akad. Nauk SSSR, 123:1, (1958), pp. 13-16.

• A translation of G. S. Makanin's 1966 Ph.D. thesis "On the Identity Problem for Finitely Presented Groups and Semigroups" (2021), arXiv:2102.00745.

• A. S. Schwartz, "The volume invariant of coverings", Dokl. Akad. Nauk SSSR 105:1, (1955).

• L. M. Shneerson, "Identities in semigroups with one defining relation", Log. Algebra Comput Math. Ivanovo Pedagog. Inst. 1:(1-2), pp. 139--156 (1972)

• L. M. Shneerson, "Identities in semigroups with one defining relation. II", Log. Algebra Comput Math. Ivanovo Pedagog. Inst. 1:(3-4), pp. 112--124 (1972)

• G. S. Tseitin, "An associative calculus with an unsolvable equivalence problem", Trudy Mat. Inst. Steklov 52, pp. 172--189 (1958)

Upcoming Talks

This semester, I'll be giving talks and/or seminars in the following locations:

• 23-Apr-2024    The freeness problem for parabolic subgroups of SL(2,C)    Seoul National University Exchange Seminar

• 09-Apr-2024   The freeness problem for parabolic subgroups of SL(2,C)    KAIST Topology Seminar (Daejeon, Korea)

Where you might have seen me talk

Here are some past talks of mine:

• 19-Mar-2024     Some decision problems in combinatorial (semi)group theory     Seoul National University Exchange Seminar 

• 29-Feb-2024     The freeness problem for parabolic subgroups of SL(2,C) Korea-France Workshop on Dynamical Group Theory (KIAS)

• 19-Feb-2024       The freeness problem for parabolic subgroups of SL(2,C) 4th EACGT (RIMS, Kyoto, Japan)

• 14-Feb-2024       The Freeness problem for parabolic subgroups of SL(2,C)    Groups, Rings, Languages (RIMS, Kyoto, Japan)

• 26-Sep-2023       Decision problems in Baumslag-Solitar-like monoids     Korea-Chile Workshop on Dynamical Group Theory (Incheon, South Korea)

• 20-Jul-2023         Membership problems for one-relator groups          Virtual Seminar on Geometry and Topology (KIAS, South Korea)

• 06-Jul-2023         The Dehn function of some one-relation monoids             Virtual Seminar on Geometry and Topology (KIAS, South Korea)

• 03-Jul-2023     One relation: the story so far TCA2023 (Pocinho, Portugal)

• 01-Jun-2023     The word problem for one-relator inverse monoids. III. Geometric Group Theory Series (Zoom), Steklov Math Inst. (Moscow, Russia)

• 25-May-2023      The word problem for one-relator inverse monoids. II. Geometric Group Theory Series (Zoom), Steklov Math Inst. (Moscow, Russia)

• 18-May-2023      The word problem for one-relator inverse monoids. I.      Geometric Group Theory Series (Zoom), Steklov Math Inst. (Moscow, Russia)

• 18-Apr-2023     Hyperbolic and one-relator groups Séminaire de Math-Info, Université Gustave Eiffel (Paris, France) 

• 05-Apr-2023     Monadic rewriting systems and the word problem Séminaire de Proofs & Algorithms, École Polytechnique (Paris, France)

• 13-Mar-2023     Language-theoretic methods in semigroup theory Séminaire de Combinatoire, École Polytechnique (Paris, France)

• 24-Feb-2023     The Dehn function of some one-relation monoids "Semigroups, Automata & Languages", CMUP. Zoom. (Porto, Portugal).

• 15-Feb-2023       Language-theoretic methods in semigroup theory Invited speaker. "Groups, Rings, Languages" (RIMS). Kyoto, Japan.

• 16-Dec-2022       Language-theoretic methods in semigroup theory IRIF automata seminar, Université Paris-Cité (Paris, France).

• 05-Dec-2022       The Dehn function of some one-relation monoids Logic Online Seminar. Zoom, Steklov Math. Institute (Moscow, Russia).

• 21-Nov-2022       The Dehn function of some one-relation monoids Algebra & Logic Seminar. Zoom, Univ. NOVA (Lisbon, Portugal). 

• 24-Oct-2022       A century-old problem in mathematical logic IMJ-PRG Séminaire Générale de Logique (Paris, France). 

• 24-Jun-2022        Free products and word-hyperbolic monoids 32nd NBSAN (York, UK)

• 21-Jun-2022     Decision problems in word-hyperbolic monoids Invited speaker. Topics in Geometric Semigroup Theory (York, UK).

• 08-Jun-2022       The word problem in semigroup theory Akita University Mathematical Sciences Seminar (Akita, Japan)

• 17-May-2022      The word problem for special semigroups University of Manchester Algebra Seminar. (Manchester, UK)

Era of online talks (due to COVID-19)

• 16-Feb-2022     Congruential languages and special rewriting systems "Groups, Rings, Languages" (RIMS Kyoto Workshop). Zoom.

• 07-Dec-2021     Le problème du mot pour les monoïdes à un relateur         Séminaire d'Informatique, Université Gustave Eiffel (Paris, France).

• 14-Oct-2021     One-relation monoids and virtually free groups University of St Andrews Pure Colloquium. Zoom. 

• 24-Jun-2021     Context-free graphs in context LMS Virtual Graduate Student Meeting. Zoom. Award for Best Talk

• 15-July-2021     The Muller-Schupp theorem for special monoids. British Early Career Mathematicians' Colloquium. Zoom.

• 04-Jun-2021     The Muller-Schupp theorem for special monoids. Invited speaker. Zassenhaus Groups & Friends Conference. Zoom.

• 11-Feb-2021       The Muller-Schupp theorem for special monoids. Newcastle University Algebra Seminar. Zoom.

• 08-Feb-2021       The Muller-Schupp theorem for special monoids. Algebra & Logic Seminar, Univ. NOVA de Lisboa. Zoom.

• 03-Feb-2021       Geometry and the word problem for special monoids York Semigroup Seminar. Zoom.

• 01-Feb-2021       Combinatorial semigroup theory. University of East Anglia Pure Maths Seminar. Zoom.

• 16-Nov-2020      The B. B. Newman Spelling Theorem. LMS Virtual Graduate Student Meeting. Zoom. Award for Best Talk

• 16-Sep-2020       The word problem for special monoids. eNBSAN (=e-North British Semigroups & Applications Network). Zoom.

Era of pre-pandemic talks

• 29-Nov-2019      Special semigroups and monadic monoids. LMS (= London Mathematical Soc.) Graduate Student Meeting. (London, UK).

• 28-Jun-2019       Decision problems for groups and semigroups. LMS Graduate Student Meeting. (London, UK).  Award for Best Talk