Continuum dynamics from quantised interaction rules

TL;DR

The paper introduces FQNM, a novel quantised transfer rule-based method for solving hyperbolic conservation laws that improves computational efficiency and preserves key physical properties.

Contribution

It presents a new paradigm for conservation-law solvers using integer transfer rules, achieving stability, accuracy, and significant speedups over traditional methods.

Findings

FQNM ensures exact conservation, monotonicity, TVD, and L1 stability.

FQNM remains stable near the Nyquist limit in high-frequency transport.

FQNM achieves order-of-magnitude speedup over floating-point baselines.

Abstract

Hyperbolic conservation laws are conventionally solved by evolving reconstructed floating-point fields, incurring both computational overhead and structural diffusion near discontinuities. Here we introduce the Fast Quantised Numerical Method (FQNM), in which the conservative operator is realised directly as an antisymmetric integer transfer rule on a countable state space, with continuum fields appearing only as reconstructed observables. For scalar conservation laws with monotone flux splitting, we establish exact conservation, monotonicity, TVD and $L^1$ stability, and convergence of the reconstructed solution to the entropy solution under $\delta/\Delta x \to 0$. We further show that distinct classical flux formulations collapse to identical dynamics whenever they induce the same integer transfer rule, identifying the transfer operator as the effective computational object. Across representative regimes, FQNM remains stable near the Nyquist limit in high-frequency transport, preserves grid-level shock structure in Burgers dynamics, and in a matched Roe-flux Sod prototype preserves shock structure at the density-scale conserved-state level relative to an exact Riemann reference, while achieving order-of-magnitude prototype acceleration over floating-point baselines. These results demonstrate that, for conservative hyperbolic dynamics, executing the operator as quantised transfer rather than reconstructed field evolution can simultaneously alter structural fidelity and reduce computational cost, establishing a new representation paradigm for conservation-law solvers.