collaborators

6 papers

math.CO2026

A Bijection between Stacked Directed Polyominoes and Motzkin Paths with Alternative Catastrophes

Florian Schager, Michael Wallner

We present a novel bijection between stacked directed polyominoes and Motzkin paths with catastrophes. Further, we leverage this new bridge between these two worlds to obtain a bet…

math.CO2026

Brick Wall Excursions: Combinatorial Interpretation of Random Flight Moments

Sergey Kirgizov, Khaydar Nurligareev, Michael Wallner

We study the expected distance of short uniform random walks in arbitrary dimensions with unit steps in random directions. It is known that for dimensions and , all the…

math.CO2026

Combinatorics of nondeterministic walks

Élie de Panafieu, Michael Wallner

This paper introduces nondeterministic walks, a new variant of one-dimensional discrete walks. The main difference to classical walks is that its nondeterministic steps consist of…

math.CO2026

A Combinatorial Framework for the Pons-Batle Identity: Young Tableaux, Lattice Paths, and Limit Laws

Hexuan Liu, Michael Wallner, Guan-Ru Yu

Tree-child networks are an important class of phylogenetic network used to model reticulate evolutionary processes. These networks have attracted increasing attention from research…

math.CO2026

The decompressed tree size of -ary chains

Michael Wallner

A chain is defined as a directed acyclic graph (DAG) with one source and one sink, where the children are ordered and the spanning tree computed using a depth-first search is a pat…

math.CO2026

Bivariate asymptotics via random walks: application to large genus maps

Andrew Elvey Price, Wenjie Fang, Baptiste Louf +1

We obtain bivariate asymptotics for the number of (unicellular) combinatorial maps (a model of discrete surfaces) as both the size and the genus grow. This work is related to two r…