Nathan Tiggemann

Research

I am currently working on applications of k-phase structures, a concept I introduced in my Master's thesis. They are closely related to quadratic enrichments of tropical varieties. Roughly, they place the same information, the "signs" of the preimages under valuation, on the variety instead of "between" the facets.

Master's thesis - k-phase structures

In my Master's thesis, I generalized real phase structures, which are defined over the real numbers, to arbitrary fields. A k-phase stores additional information to the valuation of a Puiseux-series, it collects the "signs" of the leading coefficients. These satisfy a "balancing condition". You can find the PDF here. There are a few new remarks and subsections compared to the text I handed in, the changes are noted in the beginning.

Bachelor's thesis - About the Tropicalization of the Catalecticant and the Lüroth Invariant

As the title suggests, in my Bachelor's thesis, I considered the Catalecticant and Lüroth invariant and studied how they behave under tropicalization. In particular, I studied how their properties "invariant vanishes implies the polynomial has a property" behaved for their tropicalization. The results were mostly negative. You can find my Bachelor's thesis here.
As this was my first contact with tropical geometry, this text also includes a short introduction into tropical geometry. Moreover, in the appendix you can find a horribly inefficient MatLab code for plotting tropical curves. Over at coding, you can find a way better and faster Python script for that.