Rate-Distortion Analysis of Compressed Query Delegation with Low-Rank Riemannian Updates
Faruk Alpay, Bugra Kilictas
TL;DR
This paper introduces compressed query delegation (CQD), a principled approach to reasoning under bounded working memory by compressing latent state into a low-rank tensor query, delegating to a noisy oracle, and updating the latent state with Riemannian optimization on a fixed-rank manifold. It presents a math-first formulation that links CQD to rate–distortion and information bottleneck principles, proving the optimality of spectral hard-thresholding under quadratic distortion and establishing convergence guarantees for Riemannian stochastic approximation in the presence of oracle noise. The methodology relies on a Tucker/HOSVD-based low-rank tensor model and Adaptive Spectral Masking to preserve dominant spectral content while respecting a query budget; updates are performed via retractions on the Stiefel manifold. Empirically, CQD improves bounded-context performance on a 2,500-item suite against chain-of-thought baselines and reveals a drift–gain coupling in a human benchmark across multiple oracles, highlighting a principled trade-off between information gain and representation stability in constrained reasoning tasks.
Abstract
Bounded-context agents fail when intermediate reasoning exceeds an effective working-memory budget. We study compressed query delegation (CQD): (i) compress a high-dimensional latent reasoning state into a low-rank tensor query, (ii) delegate the minimal query to an external oracle, and (iii) update the latent state via Riemannian optimization on fixed-rank manifolds. We give a math-first formulation: CQD is a constrained stochastic program with a query-budget functional and an oracle modeled as a noisy operator. We connect CQD to classical rate-distortion and information bottleneck principles, showing that spectral hard-thresholding is optimal for a natural constrained quadratic distortion problem, and we derive convergence guarantees for Riemannian stochastic approximation under bounded oracle noise and smoothness assumptions. Empirically, we report (A) a 2,500-item bounded-context reasoning suite (BBH-derived tasks plus curated paradox instances) comparing CQD against chain-of-thought baselines under fixed compute and context; and (B) a human "cognitive mirror" benchmark (N=200) measuring epistemic gain and semantic drift across modern oracles.
