Weiss derivatives of holomorphic maps
Alexis Aumonier
TL;DR
This paper develops a Weiss/unitary calculus framework to analyze the stable homotopy type of spaces of holomorphic maps to projective spaces. By proving that the unitary functor Holα(X, P(C^{n+1} ⊕ V)) is N-polynomial, it constructs a finite, functorial Weiss tower whose layers are governed by derivatives Θ_k and their U(k) actions, and it relates these to a corresponding Goodwillie tower for continuous sections. The authors give explicit identifications of the k-th derivatives, including a top derivative Θ_N, and provide concrete computations in case studies (notably degree 1 and degree (1,1) maps) that illustrate the polynomial structure and the resulting stable splittings. An application yields a conceptual proof of the Cohen–Cohen–Mann–Milgram stable splitting for rational holomorphic maps on P^1, and the work offers a roadmap for understanding unstable homology via finitely many spectral pieces and extension problems. The framework also integrates Picard-variety variations and a canonical U(1) action, enabling a robust treatment of holomorphic map spaces across line-bundle parameters.
Abstract
We propose an orthogonal approach to the stable homotopy type of spaces of holomorphic maps to projective space. We study the Weiss towers of the unitary functors of holomorphic and continuous maps to $\mathbb{P}(V)$, and show that the former is polynomial and completely compute the latter. As an application we give a new proof of a stable splitting of Cohen--Cohen--Mann--Milgram.
