Relative State Research Articles

Centering the Everett Interpretation

Abstract I propose an account of probability in the Everett interpretation of quantum mechanics. According to the account, probabilities are objective chances of centered propositions. As I show, the account solves a number of problems concerning the role of probability in the Everett interpretation. It also challenges an implicit assumption, concerning the aim and scope of fundamental physical theories, that is made throughout the philosophy of physics literature.

Quantum mechanics: how to use Everett theory practically

Among theories of the physical world, quantum mechanics remains a topic of lively discussions on its so-called interpretation. For some it remains an open question to understand how deterministic equations of this theory, as established long ago, may combine with a fundamental uncertainty. We consider the process of spontaneous emission by an atom interacting with infinite number of degrees of freedom of the electromagnetic field. There is uncertainty in the evolution of the photo-emission process which was characterized as Markovian by using the equations of quantum mechanics when the decay of the atom is due to the coupling with the vacuum field. The Markovian property leads us naturally to describe spontaneous emission by using the classical Kolmogorov equation for the probability evolution of a parameter defining the state of the atom. We explain that Everett’s many-worlds interpretation weld together our description, and appears therefore as a consequence of the equations of quantum mechanics, that solves in this case the riddle of deterministic equations describing random events.

Randomness and Irreversiblity in Quantum Mechanics: A Worked Example for a Statistical Theory.

The randomness of some irreversible quantum phenomena is a central question because irreversible phenomena break quantum coherence and thus yield an irreversible loss of information. The case of quantum jumps observed in the fluorescence of a single two-level atom illuminated by a quasi-resonant laser beam is a worked example where statistical interpretations of quantum mechanics still meet some difficulties because the basic equations are fully deterministic and unitary. In such a problem with two different time scales, the atom makes coherent optical Rabi oscillations between the two states, interrupted by random emissions (quasi-instantaneous) of photons where coherence is lost. To describe this system, we already proposed a novel approach, which is completed here. It amounts to putting a probability on the density matrix of the atom and deducing a general “kinetic Kolmogorov-like” equation for the evolution of the probability. In the simple case considered here, the probability only depends on a single variable describing the state of the atom, and yields the statistical properties of the atom under the joint effects of coherent pumping and random emission of photons. We emphasize that allows the description of all possible histories of the atom, as in Everett’s many-worlds interpretation of quantum mechanics. This yields solvable equations in the two-level atom case.

Branch-counting in the Everett interpretation of quantum mechanics

A defence is offered of a version of the branch-counting rule in the Everett interpretation (otherwise known as many worlds interpretation) of quantum mechanics that both depends on the state and is continuous in the norm topology on Hilbert space. The well-known branch-counting rule, for realistic models of measurements, in which branches are defined by decoherence theory, fails this test. The new rule hinges on the use of decoherence theory in defining branching structure, and specifically decoherent histories theory. On this basis ratios of branch numbers are defined, free of any convention. They agree with the Born rule and deliver a notion of objective probability similar to naive frequentism, save that the frequencies of outcomes are not confined to a single world at different times, but spread over worlds at a single time. Nor is it ad hoc : it is recognizably akin to the combinatorial approach to thermodynamic probability, as introduced by Boltzmann in 1879. It is identical to the procedure followed by Planck, Bose, Einstein and Dirac in defining the equilibrium distribution of the Bose–Einstein gas. It also connects in a simple way with the decision-theory approach to quantum probability.

The physics and metaphysics of Tychistic Bohmian Mechanics

The paper takes up Bell's (1987) “Everett (?) theory” and develops it further. The resulting theory is about the system of all particles in the universe, each located in ordinary, 3-dimensional space. This many-particle system as a whole performs random jumps through 3N-dimensional configuration space – hence “Tychistic Bohmian Mechanics” (TBM). The distribution of its spontaneous localisations in configuration space is given by the Born Rule probability measure for the universal wavefunction. Contra Bell, the theory is argued to satisfy the minimal desiderata for a Bohmian theory within the Primitive Ontology framework (for which we offer a metaphysically more perspicuous formulation than is customary). TBM's formalism is that of ordinary Bohmian Mechanics (BM), without the postulate of continuous particle trajectories and their deterministic dynamics. This “rump formalism” receives, however, a different interpretation. We defend TBM as an empirically adequate and coherent quantum theory. Objections voiced by Bell and Maudlin are rebutted. The “for all practical purposes”-classical, Everettian worlds (i.e. quasi-classical histories) exist sequentially in TBM (rather than simultaneously, as in the Everett interpretation). In a temporally coarse-grained sense, they quasi-persist. By contrast, the individual particles themselves cease to persist.

The Parmenidean Ascent

<i>The Parmenidean Ascent</i>

Analysis of the Mainstream Interpretation of Quantum Physics

Quantum physics is changed in an unexpected way. Scientists believe that the study of quantum physics will play an important role in future technology. Therefore, it is meaningful to study quantum physics. The aim of this paper is to provide an initial explanation of the quantum world through the classical single particle double-slit interpretation experiment, and to answer a few questions about the experiment using mainstream quantum mechanical interpretations, such as the Copenhagen interpretation and the Many-Worlds interpretation. The superposition state, which is the core of the Copenhagen interpretation, is then introduced. The Einstein-Podolsky-Rosen paradox and locality are also introduced, and the relationship between the latter and special relativity is analyzed. The author also discusses whether non-locality leads to retrocausality. Finally, the author discusses the relationship between multi-world interpretation and Schrodinger’s cat, but this may raise some philosophical questions. However, realist and hidden variable interpretation are also consistent as long as locality is abandoned.

Probability, preclusion and biological evolution in Heisenberg-picture Everett quantum mechanics

The fact that certain “extraordinary” probabilistic phenomena — in particular, macroscopic violations of the second law of thermodynamics — have never been observed to occur can be accounted for by taking hard preclusion as a basic physical law, i.e. precluding from existence events corresponding to very small but nonzero values of quantum-mechanical weight. This approach is not consistent with the usual ontology of the Everett interpretation, in which outcomes correspond to branches of the state vector, but can be successfully implemented using a Heisenberg-picture-based ontology in which outcomes are encoded in transformations of operators. Hard preclusion can provide an explanation for biological evolution, which can in turn explain our subjective experiences of, and reactions to, “ordinary” probabilistic phenomena, and the compatibility of those experiences and reactions with what we conventionally take to be objective probabilities arising from physical laws.

Making sense of Born’s rule $$p_\alpha =\Vert \varPsi _\alpha \Vert ^2$$ with the many-minds interpretation

This work is an attempt to justify Born's rule within the framework of the many-minds interpretation seen as a development of the many-worlds interpretation of Everett. More precisely, here we develop a unitary model of many-minds based on the work of Albert and Loewer (Synthese \textbf{77}, 195 (1988)). At the difference of previous models ours is not genuinely stochastic and dualistic and also involves some classical-like randomness concerning the initial conditions of the Universe. We also compare the present method for recovering Born's rule with previous works based on decision theory \emph{\`a la }Deutsch, Wallace, and envariance \emph{\`a la} Zurek and show how these approaches are connected to our model

Everett’s theory of the universal wave function

This is a tutorial for the many-worlds theory by Everett, which includes some of my personal views. It has two main parts.The first main part shows the emergence of many worlds in a universe consisting of only a Mach-Zehnder interferometer. The second main part is an abridgment of Everett's long thesis, where his theory was originally elaborated in detail with clarity and rigor. Some minor comments are added in the abridgment in light of recent developments. Even if you do not agree to Everett's view, you will still learn a great deal from his generalization of the uncertainty relation, his unique way of defining entanglement (or canonical correlation), his formulation of quantum measurement using Hamiltonian, and his relative state.

Quantum Cognition and the Mind

Clues from psychology indicate that human cognition are not only based on classical probability theory as explained by Kolmogorov’s axioms but additionally on quantum probability. Quantum probabilities lead to the conclusion that our brain adapted to the Everett many-worlds reality trough the evolutionary process. The Everett many-worlds theory views reality as a many-branched tree in which every possible quantum outcome is realized. In this context, one of the cognitive brain functions is to provide a causally consistent explanation of events to maintain self-identity over time. Causality is related to a meaningful explanation. For impossible explanations, causality does not exist, and the identity of the self breaks. Only in meaningful causal worlds may personal identities exist.

Forecasting System of Computational Time of DFT/TDDFT Calculations under the Multiverse Ansatz via Machine Learning and Cheminformatics

With the view of achieving a better performance in task assignment and load-balancing, a top-level designed forecasting system for predicting computational times of density-functional theory (DFT)/time-dependent DFT (TDDFT) calculations is presented. The computational time is assumed as the intrinsic property for the molecule. Based on this assumption, the forecasting system is established using the “reinforced concrete”, which combines the cheminformatics, several machine-learning (ML) models, and the framework of many-world interpretation (MWI) in multiverse ansatz. Herein, the cheminformatics is used to recognize the topological structure of molecules, the ML models are used to build the relationships between topology and computational cost, and the MWI framework is used to hold various combinations of DFT functionals and basis sets in DFT/TDDFT calculations. Calculated results of molecules from the DrugBank dataset show that (1) it can give quantitative predictions of computational costs, typical mean relative errors can be less than 0.2 for DFT/TDDFT calculations with derivations of ±25% using the exactly pretrained ML models and (2) it can also be employed to various combinations of DFT functional and basis set cases without exactly pretrained ML models, while only slightly enlarge predicting errors.

Many-Worlds Interpretation of Quantum Mechanics and Wave-Particle Dualism.

Based on the wave-particle duality and the principle of quantum superposition, it is shown that an elementary particle is an oscillator in which a periodic process of energy conversion takes place. Then, the transition from particle to wave, that is, the transition from one quantum state to another, is a simple change in the oscillator when the frame of reference is changed. Consequently, the many-worlds interpretation of quantum mechanics does not make sense, since there is one real Universe with elementary particles exhibiting wave and corpuscular properties.

Emergence of Objective Reality in an Irreversible Friend Thought Experiment

Recently some photon models of a Wigner’s friend experiment have led investigators to suggest that objective reality does not exist, and to publish articles with such claims. The public is not equipped to evaluate the severe limitations of these experiments. The separation of Wigner from the experiment and use of only reversible coherent processes for the friend allow operations that are not possible in ordinary reality according to the latest quantum research. We suggest directly testing the implied claim that objective reality, including incoherent objects with irreversible non-destructive memory, can be held in superposition. We suspect that it will fail, but provide for a graduated approach that may discover something about the conditions for superposition collapse. To this end, we design a thought experiment to model the objective world, investigating under what conditions experimenters in the same world (ensemble member) will be able to record a result and find it does not appear to change. This is not an investigation of hidden variables. To model the objective world, incoherent and irreversible processes must be included. To test for superposition, coherence has to be established. These seem to present a contradiction. The thought experiment suggests new places to look other than size for the origin of objective reality, casts doubt on the Many-Worlds interpretation, and provides a method of testing it.

The Quantum Handshake: An Electric Charge/Transactional Interpretation of the Single Electron Double-Slit Experiment

A new and falsifiable realist interpretation of quantum mechanics is examined in relation to the sum over histories concept, pilot wave theory and the many-worlds interpretation. This electric charge/transactional model explains how the single electron double-slit experiment produces extremely localized endpoints from diffracted wavicles, why these endpoints are scattered around the entire surface of the absorber screen, and why these points of contact result in the characteristic fringe pattern as they accumulate. Advanced waves and substantive electric charge effects in the double-slit experiment are postulated, then this hypothesis is supported by a quantitative analysis of electron emission in comparison to lightning. The wider implications if advanced waves and electric charge distribution prove to be significant factors in the double-slit experiment are discussed, including possible parallels with meteorological and neurological phenomena.

Partition function and coherent states for the quantum multiverse

Abstract Motivated by a wider acceptance of the quantum cosmology and the idea of multiverse, we follow the second and third quantization formalism for the conceptual comprehension of quantum multiverse. The other motivating feature to pursue the present study is that at the different levels of quantization the equation of quantum state is similar to that of harmonic oscillator, which encourages us to give a glancing taste of the coherent states in the domain of quantum cosmology. Third quantization enables one to model the universe as a particle in a quantum field theory of the minisuperspace and the wave description prompts one to recognize interactions among the universes of the multiverse. This picture of the system further instigates us to investigate the partition function and the thermodynamic equations of the system. The path integral formalism with proper mathematical extensions are employed to find the partition function followed by the usual techniques of statistical mechanics to examine the thermodynamic properties.

A Phenomenological Reading of the Many-Worlds Interpretation of Quantum Mechanics

The articles provides a phenomenological reading of the Many-Worlds Interpretation (MWI) of quantum mechanics and its answer to the measurement problem, or the question of “why only one of a wave function’s probable values is observed when the system is measured.” Transcendental-phenomenological and hermeneutic-phenomenological approaches are employed. The project comprises four parts. Parts one and two review MWI and the standard (Copenhagen) interpretation of quantum mechanics. Part three reviews the phenomenologies. Part four deconstructs the hermeneutics of MWI. It agrees with the confidence the theory derives from its (1) unforgiving appropriation of the Schrödinger equation and (2) association of branching universes with the evolution of the wave function insofar as that understanding comes from the formalism itself. Part four also reveals the hermeneutical shortcomings of the standard interpretation.

The Quantum Revolution in Philosophy

In this thought-provoking book, Richard Healey proposes a new interpretation of quantum theory inspired by pragmatist philosophy. Healey puts forward the interpretation as an alternative to realist quantum theories on the one hand such as Bohmian mechanics, spontaneous collapse theories, and many-worlds interpretations, which are different proposals for describing what the quantum world is like and what the basic laws of physics are, and non-realist interpretations on the other hand such as quantum Bayesianism, which proposes to understand quantum theory as describing agents' subjective epistemic states. The central idea of Healey's proposal is to understand quantum theory as providing not a description of the physical world but a set of authoritative and objectively correct prescriptions about how agents should act. The book provides a detailed development and defense of that idea, and it contains interesting discussions about a wide range of philosophical issues such as representation, probability, explanation, causation, objectivity, meaning, and fundamentality. Healey's project is at the intersection of physics and philosophy. The book is divided into two parts. Part I of the book discusses the foundational questions in quantum theory from the perspective of the prescriptive interpretation. In Part II, Healey discusses the philosophical implications of the view. Both parts are written in a way that is largely accessible to non-specialists. In this brief book review, I will focus on two questions: (1) How does Healey's idea work? (2) What reasons are there to believe in it?

An efficient quantum multiverse optimization algorithm for solving optimization problems

&lt;p&gt;Due to the recent trend of technologies to use the network-based systems, detecting them from threats become a crucial issue. Detecting unknown or modified attacks is one of the recent challenges in the field of intrusion detection system (IDS). In this research, a new algorithm called quantum multiverse optimization (QMVO) is investigated and combined with an artificial neural network (ANN) to develop advanced detection approaches for an IDS. QMVO algorithm depends on adopting a quantum representation of the quantum interference and operators in the multiverse optimization to obtain the optimal solution. The QMVO algorithm determining the neural network weights based on the kernel function, which can improve the accuracy and then optimize the training part of the artificial neural network. It is demonstrated 99.98% accuracy with experimental results that the proposed QMVO is significantly improved optimization compared with multiverse optimizer (MVO) algorithms.&lt;/p&gt;

Pan(proto)psychism and the Relative-State Interpretation of Quantum Mechanics

This paper connects the hard problem of consciousness to the interpretation of quantum mechanics. It shows that constitutive Russellian pan(proto)psychism (CRP) is compatible with Everett’s relative-state (RS) interpretation. Despite targeting different problems, CRP and RS are related, for they both establish symmetry between micro- and macrosystems, and both call for a deflationary account of Subject. The paper starts from formal arguments that demonstrate the incompatibility of CRP with alternative interpretations of quantum mechanics, followed by showing that RS entails Russellian pan(proto)psychism. Therefore, CRP and RS are mutually supportive. It then provides a unified ontological picture by combining CRP and RS. The challenge faced by CRP, the combination problem, can be resolved by adopting a RS version of quantum mechanics. Technically, this is achieved by a co-consciousness relation capable of explaining the difference between first-person and third-person perspectives. The hierarchical structure of the relation removes any concern on the structural mismatch between the physical and the phenomenal.