The projective analytic spectrum of the double of a module
Terence Gaffney, Thiago da Silva
TL;DR
This work analyzes the projectivized analytic spectrum of the double of a module, establishing that the off-diagonal fibers of the Projan of the double decompose as joins of the corresponding fibers at each point. It provides a detailed framework relating $\mathrm{Projan}(\mathcal{R}(M_D))$ to $\mathrm{Projan}(\mathcal{R}(M))$ and its extended/reduced doubles, and demonstrates how these fibers encode limiting tangent data for pairs of points on a variety. Special attention is given to curves on hypersurfaces, where the fiber over the origin can be described in terms of conormal data and the second intrinsic derivative, with explicit plane-curve results illustrating the geometry of limiting tangents and secants.
Abstract
In this work, we investigate the projectivized analytic spectrum of the double of a module, establishing some general properties, and we apply these results to $\mbox{Projan}(\cR((JM(X))_D))$ over the origin in $C\times C$, where $C$ is an irreducible curve in a hypersurface $X$.
