Papers
The core write-ups of Schur damping. For the wider literature — antecedents, independent rediscoveries, and derived works across fields — see the bibliography.
Core
- Cotton, P. (2024). Schur Complementary Allocation: A Unification of Hierarchical Risk Parity and Minimum Variance Portfolios. arXiv:2411.05807. The canonical write-up: the damped Schur complement and the recursion at arbitrary hierarchy depth, with γ interpolating HRP and minimum variance.
- Cotton, P. (2026). Two Sides of Schur Damping: High-Dimensional Pseudo-Likelihoods and Portfolio Allocation. arXiv:2606.14798. The cross-field identity: the same damping, and the same closed-form reliability γ*, in portfolio allocation and in spatial pseudo-likelihoods.
Working papers & notes
- Cotton, P. (2026). Schur Damping for Perpetual Demand Lending Pools. Working paper — PDF, web note. Proposes the interior of the dial for the single-pool-vs-two-pools decision of Chitra et al.: a partially-merged DeFi lending pool that hedges against $A - \gamma B C^{-1} B^{\mathsf T}$, with γ* set by how well the cross-pool covariance can be estimated. In the undersampled on-chain regime, γ* is pulled toward 0.