A variant of Laplace expansion and linear algebra of Druzkowski map
Li Chen
TL;DR
The paper introduces a Laplace-expansion–style identity for a class of linear equations arising from Druzkowski maps linked to the Jacobian Conjecture, enabling Cramer-type solutions built from matrix minors. In the canonical $(3,3,3)$ setting, it proves an equivalence between the existence of nontrivial linear dependencies among triple products of the $f_i$ and the vanishing of a determinant constructed from the coefficients, via Theorem 20 and Theorem unee. The framework then extends to degenerate $(2,2,2)$ and upgraded $(4,4,4)$ cases, revealing an inductive factorization structure that suggests a route toward a uniform theory for these polynomial linear systems. Together, these results provide a structured, algebraic approach to solving Druzkowski-related equations and illuminate connections between determinant identities and polynomial factorization in the study of the Jacobian Conjecture.
Abstract
Druzkowski s reduction of the Jacobian Conjecture gives rise to a class of highly complicated linear equations with polynomial coefficients. We find an unrecorded algebraic identity and apply it as a variant of the Laplace determinant expansion formula to solve such equation in a way analogous to(and no less elegant than) Cramer rule. Three consecutive cases are addressed where the situation upgrades from one case to the next.
