Resonance varieties, admissible line combinatorics and combinatorial pencils

Combinatorics of bicubic maps with hard particles

We present a purely combinatorial solution of the problem of enumerating planar bicubic maps with hard particles. This is done by use of a bijection with a particular class of blossom trees with particles, obtained by an appropriate cutting of the maps. Although these trees have no simple local characterization, we prove that their enumeration may be performed upon introducing a larger class of "admissible" trees with possibly doubly-occupied edges and summing them with appropriate signed weights. The proof relies on an extension of the cutting procedure allowing for the presence on the maps o…

关于仅含二重、三重和四重点的自由直线排列

On free line arrangements with double, triple and quadruple points

本文研究仅含二重、三重和四重点的自由实直线排列，证明其组合类型有限并列出全部容许弱组合类型，进而分类实$M$-直线排列并证明其为单纯排列。