Euclidean 4-Simplices and Invariants of Four-Dimensional Manifolds: III. Moves 1 ↔ 5 and Related Structures

Abstract

We conclude the construction of the algebraic complex, consisting of spaces of differentials of Euclidean metric values, for four-dimensional piecewise-linear manifolds. Assuming that the complex is acyclic, we investigate how its torsion changes under rebuildings of the manifold triangulation. First, we write out formulas for moves 3 -> 3 and 2 <-> 4 based on the results of our two previous works, and then we study in detail moves 1 <-> 5. On this basis, we obtain the formula for a four-dimensional manifold invariant. As an example, we present a detailed calculation of our invariant for sphere S^4; in particular, the complex turns out, indeed, to be acyclic.