An arithmetic enrichment of Bézout's Theorem

S McKean - Mathematische Annalen, 2021 - Springer
The classical version of Bézout's Theorem gives an integer-valued count of the intersection
points of hypersurfaces in projective space over an algebraically closed field. Using work of …

[HTML][HTML] Quadratic types and the dynamic Euler number of lines on a quintic threefold

S Pauli - Advances in Mathematics, 2022 - Elsevier
We provide a geometric interpretation of the local contribution of a line to the count of lines
on a quintic threefold over a field k of characteristic not equal to 2, that is, we define the type …

Bézoutians and the 𝔸1-degree

T Brazelton, S McKean, S Pauli - Algebra & Number Theory, 2023 - msp.org
We prove that both the local and global 𝔸 1-degree of an endomorphism of affine space can
be computed in terms of the multivariate Bézoutian. In particular, we show that the Bézoutian …

[PDF][PDF] The trace of the local A1-degree

T Brazelton, R Burklund, S McKean… - Homology …, 2021 - services.math.duke.edu
We prove that the local A 1-degree of a polynomial function at an isolated zero with finite
separable residue field is given by the trace of the local A1-degree over the residue field …

Bitangents to plane quartics via tropical geometry: rationality, -enumeration, and real signed count

H Markwig, S Payne, K Shaw - Research in the Mathematical Sciences, 2023 - Springer
We explore extensions of tropical methods to arithmetic enumerative problems such as A 1-
enumeration with values in the Grothendieck–Witt ring and rationality over Henselian valued …

Combinatorics and real lifts of bitangents to tropical quartic curves

MA Cueto, H Markwig - Discrete & Computational Geometry, 2023 - Springer
Smooth algebraic plane quartics over algebraically closed fields of characteristic different
than two have 28 bitangent lines. Their tropical counterparts often have infinitely many …

Arithmetic counts of tropical plane curves and their properties

AJ Puentes, H Markwig, S Pauli, F Röhrle - Advances in Geometry, 2024 - degruyter.com
Recently, the first and third author proved a correspondence theorem which recovers the
Levine-Welschinger invariants of toric del Pezzo surfaces as a count of tropical curves …

Conics meeting eight lines over perfect fields

C Darwin, A Galimova, MP Gu, S McKean - Journal of Algebra, 2023 - Elsevier
Over the complex numbers, there are 92 plane conics meeting 8 general lines in projective 3-
space. Using the Euler number and local degree from motivic homotopy theory, we give an …

Avoidance loci and tropicalizations of real bitangents to plane quartics

H Markwig, S Payne, K Shaw - Proceedings of the Royal Society of …, 2024 - cambridge.org
We compare two partitions of real bitangents to smooth plane quartics into sets of 4: one
coming from the closures of connected components of the avoidance locus and another …

Bitangents of real algebraic curves: signed count and constructions

T Blomme, E Brugallé, C Garay - arXiv preprint arXiv:2402.03993, 2024 - arxiv.org
We study real bitangents of real algebraic plane curves from two perspectives. We first show
that there exists a signed count of such bitangents that only depends on the real topological …