Tim Gräfnitz

I am a Postdoctoral researcher at Leibniz University Hannover work in Algebraic Geometry.

My research focuses on moduli spaces, deformations, enumerative invariants and mirror symmetry, employing techniques from logarithmic and tropical geometry.

I received my PhD from University of Hamburg in 2021. I then held postdoctoral positions at Ruhr-University Bochum and University of Cambridge before starting at Leibniz University in 2023.

Here is my CV.

Research interests: Algebraic Geometry, Logarithmic Geometry, Tropical Geometry, Enumerative Geometry, Mirror Symmetry, Birational Geometry.

Publications and preprints:

Relations between 2-marked log Gromov-Witten invariants and the tropical evaluation curve, in preparation.
Smoothings from zero mutable Laurent polynomials via log resolutions and divisorial extractions, arXiv:2503.18661, 2025.
Singular Log Structures and Log Crepant Log Resolutions I (with Alessio Corti and Helge Ruddat), arXiv:2503.11610, 2025.
Enumerative geometry of quantum periods (with Helge Ruddat, Eric Zaslow and Benjanmin Zhou), arXiv:2502.19408, 2025.
Gromov-Witten invariants and mirror symmetry for non-Fano varieties using scattering diagrams (with Per Berglund and Michael Lathwood), arXiv:2404.16782, 2024.
The dense region in scattering diagrams (with Patrick Luo), Bulletin of the Australian Mathematical Society (2025), 1-13, arXiv:2312.13990, 2023.
Counting (tropical) curves via scattering.sage, arXiv:2210.10455, 2022.
The proper Landau-Ginzburg potential is the open mirror map (with Helge Ruddat and Eric Zaslow), Advances in Mathematics 447 (2024), 109639, arXiv:2204.12249, 2022.
Theta functions, broken lines and 2-marked log Gromov-Witten invariants, arXiv:2204.12257, 2022.
Tropical correspondence for smooth del Pezzo log Calabi-Yau pairs, Journal of Algebraic Geometry 31 (2022) 4, 687-749, arXiv:2005.14018, 687–749, 2020.

Theses:

Doctoral thesis: Tropical correspondence for smooth del Pezzo log Calabi-Yau pairs, 2020.
Master thesis: Tropicalization of the Lines on the Dwork Pencil if Quintic Threefolds, 2017.

Sage codes:

scattering.sage: A sage code computing scattering diagrams and wall structures in the Gross-Siebert program.
mutation.sage: A sage code computing mutation graphs of zero mutable Laurent polynomials.
tomjerry.sage: A sage code computing dual pairs of zero mutable Laurent polynomials on rectangular triangles.

Contact:
E-Mail: graefnitz(at)math(dot)uni-hannover(dot)de