Beyond Harnack Amoeba Boundaries
Abstract
We construct smooth irreducible plane curves whose complete amoeba contour is a smooth embedded curve equal to the amoeba boundary, although the curves are not torically equivalent to simple Harnack curves. Finite monomial coverings yield explicit infinite families with higher logarithmic multiplicity and nonmaximal normalized amoeba area. We classify the Newton polygons admitting such covering constructions through their exponent lattices, give an exact connectedness criterion in terms of monodromy, and treat primitive polygons by a separate phase-sensitive construction. Exact triangular and trapezoidal families are complemented by positive-genus investigations exhibiting bounded amoeba-complement components. These results show that a perfectly exposed amoeba contour does not determine the real structure, logarithmic sheet number, or Harnack type of the underlying curve.
Related
BibTeX
@misc{nisse2026beyond,
title = {{Beyond Harnack Amoeba Boundaries}},
author = {Mounir Nisse},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.15607},
eprint = {2610.15607},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.15607},
}
RIS
TY - UNPB
TI - Beyond Harnack Amoeba Boundaries
AU - Mounir Nisse
PY - 2026
DA - 2026/10/11
PB - arXiv
DO - 10.48550/arxiv.2610.15607
UR - https://arxiv.org/abs/2610.15607
AB - We construct smooth irreducible plane curves whose complete amoeba contour is a smooth embedded curve equal to the amoeba boundary, although the curves are not torically equivalent to simple Harnack curves. Finite monomial coverings yield explicit infinite families with higher logarithmic multiplicity and nonmaximal normalized amoeba area. We classify the Newton polygons admitting such covering constructions through their exponent lattices, give an exact connectedness criterion in terms of monodromy, and treat primitive polygons by a separate phase-sensitive construction. Exact triangular and trapezoidal families are complemented by positive-genus investigations exhibiting bounded amoeba-complement components. These results show that a perfectly exposed amoeba contour does not determine the real structure, logarithmic sheet number, or Harnack type of the underlying curve.
ER -