Latest Publications

  • Open Access

    Local Credit Assignment for CPU Transformers: Readout Consensus and the Cost of Predictive Coding

    by Vikram Lex

    Local objectives expose parallelism across Transformer depth but remove downstream credit. We study this trade-off in two complementary experiments on central processing units (CPUs). A prospectively specified campaign on 24-layer byte-level Transformers evaluates readout-gradient consensus (RGC), which coordinates shared-readout parameter gradients without restoring cross-stage activation gradients. Asynchronous RGC reaches 1.382 times backpropagation throughput, while process-tree memory rises from 1.94 to 4.31 GiB and active worker threads increase from 24 to 29; RGC itself received no held-out quality test. Validation selected asynchronous broadcast, which transports no readout gradients, as the candidate for the held-out test, and broadcast fails its 1% non-inferiority criterion; TinyStories transfer and the primary readout-equivalence criterion also fail. A separate, exploratory 27-run study applies stage-boundary augmented Lagrangian predictive coding (PC-ALM) to a smaller 12-layer Transformer. Three inference rounds produce a small but nonzero mean paired validation-loss gap of +0.142% versus backpropagation at 2.78 times its serial training time. Initialising multipliers from local readout gradients degrades learning; penalty-only predictive coding retains much of the quality benefit. We provide a readout-information counterexample, a feasible-stationary-point gradient identity, and a linear conditioning diagnostic, with explicit limits on their implications. The evidence identifies two distinct costs: quality lost by truncating credit and computation spent recovering it. It establishes neither quality-preserving CPU acceleration nor a general replacement for backpropagation.

  • Open Access

    Bounded-Horizon Local Transformer Training on CPUs: Quality, Throughput, and Memory

    by Vikram Lex

    Background : Local objectives expose parallelism across network depth by removing cross-stage backward dependencies, but they alter end-to-end credit assignment and complicate ownership of a shared output readout. Objectives : We evaluate the quality, throughput, and memory trade-off of bounded-horizon local training for 24-layer byte-level Transformers on a many-core CPU, and investigate how upstream local losses should participate in shared-readout updates. Methods : We introduce readout-gradient consensus (RGC), in which upstream stages differentiate local losses through same-microbatch readout snapshots and the final stage averages their contributions. Six matched methods are evaluated under a prospectively specified protocol using paired seeds, held-out testing, repeated systems measurements, two corpora, and three model widths. Results : On a 31-core allocation, asynchronous RGC reaches 1.382 times the throughput of matched global backpropagation, with a paired 95% interval from 1.364 to 1.400, while peak process-tree proportional set size increases from 1.94 to 4.31 GiB. The comparison uses 29 stage-worker threads versus 24 intra-operation threads for backpropagation. The selected asynchronous broadcast method has a held-out mean quality gap of 0.841%, but its one-sided 95% upper bound is 2.095%; therefore, the prespecified 1% non-inferiority criterion is not met. Additional enwik8 widths satisfy their joint criteria, whereas TinyStories does not, and readout equivalence is not established. Conclusions : The evidence supports a bounded CPU quality-throughput-memory frontier for this implementation, not quality-preserving training or a general readout-recovery mechanism.

  • Open Access

    QHM: Unifying Superconducting and Topological Quantum Computing with Multimodal AI

    by Vikram Karlex

    Artificial Intelligence (AI) has achieved remarkable successes, but it continues to face critical challenges—including inefficiency, limited interpretability, lack of robustness, alignment issues, and high energy consumption. Quantum computing offers a promising path to fundamentally accelerate and enhance AI by leveraging quantum parallelism and entanglement. This paper proposes QHM—Quantum Hybrid Multimodal, a unified framework that integrates superconducting and topological quantum computing into multimodal AI architectures. We establish a theoretical foundation for embedding quantum subroutines—such as a Quantum Self-Attention Neural Network (QSANN) and Quantum Enhanced Quantum Approximate Optimization Algorithm (QAOA)- QQAOA—within classical deep learning models. We survey key quantum algorithms, including Grover’s search, the HHL algorithm for solving linear systems, QAOA, and variational quantum circuits, evaluating their computational complexity and suitability for AI workloads. We also analyze cutting-edge quantum hardware platforms: superconducting qubit systems like Google’s 105-qubit Willow, IBM’s 1,121-qubit Condor, Amazon’s bosonic Ocelot, and Microsoft’s topological Majorana-1, discussing their potential for accelerating AI. The paper explores how quantum resources can enhance large language models, Transformers, mixture-of-experts architectures, and cross-modal learning via quantum-accelerated similarity search, attention mechanisms, and optimization techniques. We also examine practical engineering challenges, including cryogenic cooling, control electronics, qubit noise, quantum error correction, and data encoding overhead, offering a cost-benefit analysis. An implementation roadmap is outlined, progressing from classical simulations to hybrid quantum-classical prototypes, and ultimately to fully integrated systems. We propose benchmarking strategies to evaluate quantum-AI performance relative to classical baselines. Compared to conventional approaches, the QHM hybrid framework promises improved computational scaling and novel capabilities—such as faster search and more efficient training—while acknowledging current limitations in noise and infrastructure. We conclude by outlining future directions for developing quantum-enhanced AI systems that are more efficient, interpretable, and aligned with human values, and we discuss broader implications for AI safety and sustainability.