The Geometric Origin of the Cayley-Hamilton Theorem: A Constructive Proof via Dimensional Syzygy
Abstract
We demonstrate that the Cayley-Hamilton theorem is a derived consequence of a more fundamental dimensional constraint: the syzygy formed by the tensor product of two Levi-Civita symbols, which vanishes identically in m-dimensional space. By shifting perspective from the tensor A to the isotropic operators that induce A's invariants through contraction, we reveal that the Cayley-Hamilton identity emerges when this vanishing operator acts on the m-fold tensor product of A. The intrinsic tensorial form of the theorem--invariant coefficients multiplying tensor powers--is inherited from the contraction structure rather than imposed ad hoc. We provide explicit verification for two-dimensional space and a dimension-independent proof using Laplace expansion combined with Newton-Girard identities. This framework clarifies why the theorem's structure depends on ambient dimension and suggests extensions to higher-order tensors where classical characteristic polynomial methods fail.
Keywords
Cite
@article{arxiv.2601.06136,
title = {The Geometric Origin of the Cayley-Hamilton Theorem: A Constructive Proof via Dimensional Syzygy},
author = {Xiao Wang},
journal= {arXiv preprint arXiv:2601.06136},
year = {2026}
}
Comments
9 pages, 1 appendix. Prepared for Mechanics Research Communications