Erik Paemurru

Links: arXiv, ORCID, GitHub.

About Me

As of August 2025, I am working in the Theory of Atoms research group of Prof. Ludmil Katzarkov at Institute of Mathematics and Informatics at the Bulgarian Academy of Sciences, Sofia, Bulgaria. I received my PhD in December 2020 from Loughborough University, UK, my advisor was Prof. Hamid Abban.

My research interests include birational geometry of singular Fano varieties, especially nonrationality problems and Sarkisov links. Fano varieties are central in geometry, generalising the sphere to higher dimensions. Fano varieties also have close connections to physics, as the anticanonical sections of Fano varieties provide the main construction of Calabi–Yau manifolds used in string theory. In a recent work, inspired by ideas from mirror symmetry, the nonrationality of very general cubic fourfolds was proved using the theory of atoms. While in Sofia, I plan to study the theory of atoms, its applications to nonrationality questions and its connections to noncommutative spectra. I am also interested in computer algebra and I am one of the developers of the OSCAR computer algebra system.

Below are the previous academic positions I have held:

Contact

Email: algebraicgeometry [at] runbox [dot] com

Institute of Mathematics and Informatics
Bulgarian Academy of Sciences
Acad. G. Bonchev Str., Bl. 8
Sofia 1113, Bulgaria

Publications

  1. Log canonical thresholds of high multiplicity reduced plane curves (joint with N. Viswanathan), to appear in Glasgow Mathematical Journal, arXiv:2311.00963
  2. Counting divisorial contractions with centre a cAₙ-singularity, Publications of the Research Institute for Mathematical Sciences, Kyoto University 60 (2024), no. 4, 699–721, doi:10.4171/prims/60-4-2
  3. Birational geometry of sextic double solids with a compound Aₙ singularity, Nagoya Mathematical Journal (2024), 1–52, doi:10.1017/nmj.2024.17
  4. 2n²-inequality for cA₁ points and applications to birational rigidity (joint with I. Krylov, T. Okada, J. Park), Compositio Mathematica 160 (2024), no. 7, 1551–1595, doi:10.1112/S0010437X24007164
  5. Reading the log canonical threshold of a plane curve singularity from its Newton polyhedron, Annali dell’ Università di Ferrara 70 (2024), 1069–1082, doi:10.1007/s11565-024-00524-6
  6. Del Pezzo Surfaces in Weighted Projective Spaces, Proceedings of the Edinburgh Mathematical Society 61(2) (2018), doi:10.1017/S0013091517000335

Preprints

  1. Local inequalities for cAₖ singularities (joint with I. Krylov, T. Okada), arXiv preprint 2025, arxiv:2508.21676
  2. Birational models of smooth Fano hypersurfaces (joint with L. Campo, T. Guerreiro), arXiv preprint 2023, submitted to New York Journal of Mathematics, arXiv:2311.11386

Invited talks and presentations

Local inequalities for terminal 3-folds and applications to birational rigidity
Geometry at Large, Burgas, Bulgaria
Aug 2025
Local inequalities for cAₖ singularities
May 2025
Birational rigidity of Fano 3-folds with compound A_k singularities
Dec 2024
Birational rigidity of Fano 3-folds with compound A_k singularities
Oberseminar Algebraische Geometrie, Saarbrücken, Germany
Dec 2024
Algorithmic Sarkisov Program
Poster presentation, evaluation of the SFB-TRR 195 by the DFG committee, Aachen, Germany
Jul 2024
Restrictions of toric weighted blowups
Algebraic Geometry Conference, Basel, Switzerland
Dec 2023
Explicit Sarkisov links
Oberseminar Algebraische Geometrie, Saarbrücken, Germany
Nov 2023
Sarkisov links of projective 3-space initiated by a divisorial contraction with centre a point
IBS Algebraic Geometry Seminar, Pohang, South Korea
Oct 2023
Log canonical thresholds of high multiplicity plane curves
Sept 2023
Log canonical thresholds of high multiplicity plane curves
Generalized and Symplectic Geometry, Sunny Beach, Bulgaria
Aug 2023
Log canonical thresholds of high multiplicity plane curves
Jun 2023
Divisorial contractions and local analytic equivalence
Feb 2023
2n²-inequality and applications to birational rigidity
Dec 2022
Parameter space of divisorial contractions
Aug 2022
Aug 2022
Counting divisorial contractions with centre a cAₙ-singularity
Algebraic Geometry Seminar, visiting Jihun Park in IBS, Pohang, South Korea
Jul 2022
Apr 2022
Apr 2022
Feb 2022
All divisorial contractions are valuation-blowups
Oct 2021
Birational geometry of sextic double solids with a compound Aₙ singularity
Jun 2021
Feb 2021
Birational models of terminal sextic double solids
Fanosearch, London, UK
Jun 2020
Birational models of terminal sextic double solids
Geometry Seminar, visiting Igor Krylov in KIAS, Seoul, South Korea
Dec 2019
Classification of simple singularities
Bernoullis Tafelrunde, Basel, Switzerland
Dec 2019
Birational models of terminal sextic double solids
Dec 2019
Birational models of terminal sextic double solids
Aug 2019
Birational models of terminal sextic double solids
Jun 2019
Elliptic curves over finite fields
Seminar, Tartu, Estonia
Jun 2019
Classification of simple singularities
Jan 2019
Birational models of terminal sextic double solids
8th swiss-french workshop in Algebraic Geometry, Charmey, Switzerland
Jan 2019
Introduction to algebraic geometry for cryptographers
Seminar, Tartu, Estonia
Dec 2018
Determining singularity type of Fano hypersurfaces
Jul 2018
Birational geometry of Fano 3-folds
Annual Conference of Mathematics Research Students, Loughborough, UK
May 2018
Birational models of terminal sextic double solids
Feb 2018
Del Pezzo Surfaces in Weighted Projective Spaces
Jun 2013

Teaching

Complex Geometry
Lecturer, Saarland University, 7 students
Spring 2025
Elliptic Curves
Reading Seminar, Saarland University, 5 students, cms.sic.saarland/elliptische_kurven
Winter 2024
Homological Mirror Symmetry
Reading Seminar, University of Miami, 5 postdocs
Spring 2022
Calculus II
Lecturer, University of Miami, 15 students
Spring 2022
Linear Algebra II
Teaching assistant, University of Basel, Marking, 60 students
Spring 2021
Computer course (LaTeX, Matlab, Maple)
Teaching assistant, University of Basel, Lab and via Zoom, 60 students
Autumn 2020
Functional Programming
Teaching assistant, Loughborough University, Lab, 75 students
Autumn 2018, 2019
Communicating Mathematics
Teaching assistant, Loughborough University, Lab, 50 students
Spring 2018
Analysis 3
Teaching assistant, Loughborough University, Exercise classes, 40 students
Autumn 2017
Organiser of weekly geometry PhD student seminars
Reading seminar, Loughborough University, 5 PhD students, https://sites.google.com/site/geomsslboro/
2017–2020
Coach of the Estonian team for the International Mathematical Olympiad
20 training sessions for 6 to 26 students
2011–2018