We study bitangents of non-smooth tropical plane quartics. Our main result is that with appropriate multiplicities, every such curve has 7 equivalence classes of bitangent lines. Moreover, the multiplicity of bitangent lines varies continuously in families of tropical plane curves.

中文翻译：

---

非光滑热带四次方程的双切线

我们研究非光滑热带平面四次方程的双切线。我们的主要结果是，通过适当的多重性，每条这样的曲线都有 7 个等价类的双切线。此外，双切线的多样性在热带平面曲线族中不断变化。