arXiv:1802.10136

Hidden Variable Quantum Mechanics from Branching from Quantum Complexity

Don Weingarten

Published Feb 27, 2018• 1 citation

Abstract

Beginning with the Everett-DeWitt many-worlds interpretation of quantum mechanics, there have been a series of proposals for how the state vector of a quantum system might be split at any instant into orthogonal branches, each of which exhibits approximately classical behavior. Here we propose a decomposition of a state vector into branches by finding the minimum of a measure of the net quantum complexity of the branch decomposition. We then propose a method for finding an ensemble of possible initial state vectors from which a randomly selected member, if evolved by ordinary Hamiltonian time evolution, will follow a single sequence of those branches of many-worlds quantum mechanics which persist through time. Macroscopic reality, we hypothesize, consists of an accumulating sequence of such persistent branching results. For any particular draw, the resulting deterministic system appears to exhibit random behavior as a result of the successive emergence over time of information present in the initial state but not previously observed.

DOI: 10.48550/arxiv.1802.10136

Related papers

Hidden Variable Theory of a Single World from Many-Worlds Quantum Mechanics

Don Weingarten

We propose a method for finding an initial state vector which by ordinary Hamiltonian time evolution follows a single branch of many-worlds quantum mechanics. The resulting deterministic system appears to exhibit random behavior as a result of the successive emergence over time of information present in the initial state but not previously observed.

arXiv:1709.05777Sep 18, 20171 citation

Wavefunction branches demand a definition!

C. Jess Riedel

Under unitary evolution, a typical macroscopic quantum system is thought to develop wavefunction branches: a time-dependent decomposition into orthogonal components that (1) form a tree structure forward in time, (2) are approximate eigenstates of quasiclassical macroscopic observables, and (3) exhibit effective collapse of feasibly measurable observables. If they could be defined precisely, wavefunction branches would extend the theory of decoherence beyond the system-environment paradigm and could supplant anthropocentric measurement in the quantum axioms. Furthermore, when such branches have bounded entanglement and can be effectively identified numerically, sampling them would allow asymptotically efficient classical simulation of quantum systems. I consider a promising recent approach to formalizing branches on the lattice by Taylor & McCulloch [Quantum 9, 1670 (2025), arXiv:2308.04494], and compare it to prior work from Weingarten [Found. Phys. 52, 45 (2022), arXiv:2105.04545]. Both proposals are based on quantum complexity and argue that, once created, branches persist for long times due to the generic linear growth of state complexity. Taylor & McCulloch characterize branches by a large difference in the unitary complexity necessary to interfere vs. distinguish them. Weingarten takes branches as the components of the decomposition that minimizes a weighted sum of expected squared complexity and the Shannon entropy of squared norms. I discuss strengths and weaknesses of these approaches, and identify tractable open questions.

arXiv:2506.15663Jun 16, 20250 citations

The Many Worlds Interpretation

Jonathan Allday

The hidden variable theories are, more cumbersome and artificial—while the Copenhagen interpretation is hopelessly incomplete because of its a priori reliance on classical physics, as well as a philosophic monstrosity with a “reality” concept for the macroscopic world and denial of the same for microcosm. In recent work on the Everett (Many-Worlds) interpretation of quantum mechanics, it has increasingly been recognized that any version of the interpretation worth defending will be one in which the basic formalism of quantum mechanics is left unchanged. Properties such as the interpretation of wave-function as describing a multiverse of branching worlds, or the ascription of probabilities to the branching events, must be emergent from the unitary quantum mechanics rather than added explicitly to the mathematics. Deutsch’s strategy was to introduce a few assumptions from decision theory into the Everett interpretation and then to show how they work with quantum theory to create a natural value measure that is the same as the expectation value.

CRC Press eBooksSep 21, 20221 citation

Intrinsic Hilbert Space Decomposition and the Origin of Quantum Probabilities

Atsushi Okamoto

We propose a framework, referred to as the Intrinsic Observability Framework (IOF), in which the probabilistic structure of quantum mechanics arises from an intrinsic decomposition of the Hilbert space into observable and hidden degrees of freedom. The total system is described by a pure state evolving unitarily, while observable states are obtained by restricting the description to the observable sector via a partial trace over the hidden sector. A key assumption of the present approach is that this decomposition is a fundamental and non-contextual feature of the system, rather than a modeling choice or a consequence of environmental interactions. The hidden degrees of freedom introduced here are not interpreted as unmeasured physical variables, but as components that are fundamentally excluded from the space of observable quantities. Within the IOF, mixed states and probabilistic outcomes emerge from incomplete access to the full state, without invoking intrinsic randomness, external environments, or branching worlds. This distinguishes the present formulation from decoherence-based approaches, hidden-variable theories, and many-worlds interpretations. The proposed framework provides an alternative structural perspective on the origin of quantum probabilities while preserving the standard unitary formalism. We discuss its conceptual implications and outline directions for future work.

Apr 21, 20260 citations

On a deterministic disguise of orthodox quantum mechanics

Ulrich Mutze

According to quantum theory, pure physical states correspond to equivalence classes of state vectors, where any two members of one class differ by a complex factor. The point is that such a factor does not change the probability for the occurrence of any measurement result as computed within the formalism of quantum mechanics. In the formalism to be presented here, the state vector does not only determine the probabilities for the occurrence of measurement results, rather it determines the result itself. The information which guides the selection process is obtained from the state vector in a way that is not invariant against multiplication by a complex factor. It can be seen as a kind of global phase of the state vectors. This global phase then is a perfectly hidden variable. For this presentation of quantum mechanics we have a remarkable parallelism to classical statistical mechanics: If we would know exactly the initial state of a system, we could compute the outcomes for all experiments to be done later on this system. In the quantum case the initial state is to be represented by its state vector with specified phase, e.g. as a concrete complex-valued wave function.

arXiv:1701.07236Jan 25, 20170 citations

Reconstruction of Schrödinger's Cat in Many Worlds 4; The Emergent Structure of Many-Worlds Interpretation and Its Self-Consistency Foundation

changzheng zhou, ZIQING zhou

This paper constructs a logically self-consistent emergent structural frameworkfor the Many-Worlds Interpretation (MWI) based on decoherence theory, quantum information geometry, and self-referential dynamics. Within this framework,a ”world” is rigorously defined as a quasi-classical branch formed in Hilbert spacethrough environmental decoherence and information-geometric boundaries. Its independence is quantitatively characterized by the branch separation degree Dab defined by the quantum relative entropy between branches. When Dab exceeds a critical value Dc determined jointly by the energy scale of environmental fluctuationsand the decoherence time, the branches separate irreversibly in the informationgeometric sense, constituting independent ”worlds”. Furthermore, by introducingthe concept of a self-consistent observer, this paper demonstrates the dynamic selection mechanism of cosmological laws within the string theory landscape: only thosevacuum branches that can support self-consistent observers (satisfying conditionssuch as the memory decoherence time being much greater than the cognitive operation time) have their wavefunction weights effectively preserved during evolution,thereby acquiring physical reality. Finally, combining Zurek’s envariance argumentwith the requirement of observer memory stability, we show that the Born ruleP(i) = |⟨i|ψ⟩|2 is not an additional assumption but a necessary consequence forthe stable existence of self-consistent observers. This framework provides an operational mathematical foundation for the many-worlds interpretation, transforms theanthropic principle into a dynamic selection problem, and offers an explanation forthe origin of probability based on quantum information principles.

Mar 5, 20260 citations