High-Dimensional $p$-Normed Flows

TL;DR

This paper extends classical graph flow theory to $d$-dimensional $p$-normed flows, establishing bounds on flow indices for various graph classes and connecting these to longstanding conjectures.

Contribution

It introduces $d$-dimensional $p$-normed nowhere-zero flows, defines the flow index $_{d,p}(G)$, and establishes new bounds and properties, extending classical flow results to arbitrary norms.

Findings

Established upper bounds for flow indices, e.g., $_{2,p}(G) ext{ and } _{3,p}(G)$

Proved $_{k,p}(G) = 2$ for graphs with certain cycle covers

Connected flow theory with geometric and topological perspectives

Abstract

We generalize Tutte's integer flows and the $d$-dimensional Euclidean flows of Mattiolo, Mazzuoccolo, Rajn\'{i}k, and Tabarelli to \emph{$d$-dimensional $p$-normed nowhere-zero flows} and define the corresponding flow index $\phi_{d,p}(G)$ to be the infimum over all real numbers $r$ for which $G$ admits a $d$-dimensional $p$-normed nowhere-zero $r$-flow. For any bridgeless graph $G$ and any $p\ge 1$, we establish general upper bounds, including $\phi_{2,p}(G) \le 3$, $\phi_{3,p}(G) \le 1+\sqrt{2}$, and tight bounds for graphs admitting a $4$-NZF. For graphs with oriented $(k+1)$-cycle $2l$-covers, we show that $\phi_{k,p}(G) = 2$, which implies $\phi_{2,p}(G) = 2$ for graphs admitting a nowhere-zero $3$-flow and $\phi_{3,p}(G) = 2$ for those admitting a nowhere-zero $4$-flow. These results extend classical flow theory to arbitrary norms, provide supporting evidences for Tutte's $5$-flow Conjecture and Jain's $S^2$-Flow Conjecture, and connect combinatorial flows with geometric and topological perspectives.