English

Exponential complexity and ontological theories of quantum mechanics

Quantum Physics 2008-02-15 v2

Abstract

Ontological theories of quantum mechanics describe a single system by means of well-defined classical variables and attribute the quantum uncertainties to our ignorance about the underlying reality represented by these variables. We consider the general class of ontological theories describing a quantum system by a set of variables with Markovian (either deterministic or stochastic) evolution. We provide the first proof that the number of continuous variables can not be smaller than 2N-2, N being the Hilbert space dimension. Thus, any ontological Markovian theory of quantum mechanics requires a number of variables which grows exponentially with the physical size. This result is relevant also in the framework of quantum Monte Carlo methods.

Keywords

Cite

@article{arxiv.0711.4770,
  title  = {Exponential complexity and ontological theories of quantum mechanics},
  author = {Alberto Montina},
  journal= {arXiv preprint arXiv:0711.4770},
  year   = {2008}
}
R2 v1 2026-06-21T09:48:43.951Z