Hydrodynamic and symbolic models of computation with advice

Dynamical systems and physical models defined on idealized continuous phase spaces are known to exhibit non-computable phenomena; examples include the wave equation, recurrent neural networks, or Julia sets in holomorphic dynamics. Inspired by the works of Moore and Siegelmann, we show that ideal fl...

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Bibliographic Details
Published in:Revista matemática iberoamericana Vol. 41; no. 1; pp. 313 - 338
Main Author: Cardona, Robert
Format: Journal Article
Language:English
Published: 01.01.2025
ISSN:0213-2230, 2235-0616
Online Access:Get full text
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Summary:Dynamical systems and physical models defined on idealized continuous phase spaces are known to exhibit non-computable phenomena; examples include the wave equation, recurrent neural networks, or Julia sets in holomorphic dynamics. Inspired by the works of Moore and Siegelmann, we show that ideal fluids, modeled by the Euler equations, are capable of simulating poly-time Turing machines with polynomial advice on compact three-dimensional domains. This is precisely the complexity class P/\textup{poly} considered by Siegelmann in her study of analog recurrent neural networks. In addition, we introduce a new class of symbolic systems, related to countably piecewise linear transformations of the unit square, that is capable of simulating Turing machines with advice in real-time, contrary to previously known models.
ISSN:0213-2230
2235-0616
DOI:10.4171/rmi/1506