Quantum Theories

The two fundamental pillars of physics for over 100 years have been quantum theory and general relativity, but their unification at short distances remains elusive, both technically and conceptually. This work is a philosophical investigation of the second kind of problem, and in particular of the striking fact that in many approaches to ‘quantum gravity’ classical spacetime structures are not merely quantized, but arguably absent—so that spacetime is not merely a classical limit, but ‘emergent’. This issue is not only central (...) to the problem of quantum gravity, but of deep significance for our philosophical understanding of physical reality, promising a conceptual revolution at least as profound as Einstein’s. We give an introduction to the question of spacetime emergence in general, for philosophers of metaphysics and science, and argue that spacetime functionalism explains how something non-spatiotemporal could ever appear as space and time. More technical chapters investigate the issue in detail for causal set theory, loop quantum gravity, and string theory, and the book also serves as a philosophical introduction to those theories for philosophers of physics. Our results help physicists clarify what new conceptual framework—not resting on space and time—may be necessary to achieve a theory of quantum gravity; and show philosophers how the world may not be spatiotemporal at root, and what kind of a world we might then live in. (shrink)

This paper presents Version 3 (V3) of the Multi‑Simulation Thesis (MST). Building on the systematic framework of V2—which interpreted quantum phenomena as computational signatures—V3 advances MST toward a testable research program. It identifies potential falsifiability pathways, including probes for Planck‑scale discreteness, pseudorandomness in quantum processes, anomalies in quantum‑computing noise spectra, and cosmological “compression artifacts.” V3 further extends MST into cosmological and teleological dimensions, reframing dark matter, fine‑tuning, and universal expansion as possible features of the simulation codebase. Finally, it explores the (...) “purpose clause,” suggesting interpretations of MST as ancestor simulation, consciousness laboratory, stress test, or narrative generator. By offering falsifiable predictions and experimental heuristics, V3 moves MST beyond metaphysics, proposing it as a speculative but fertile scientific research program. (shrink)

Introduced is a single, pre-registered coherence ratio τ = S/(D+ε) and we test its falsifiable predictions across language models and EEG, running all eligible public datasets and benchmarks under a frozen configuration. We specify hard failure modes (ICC, ∆AUC/∆R2, equivalence via TOST) and include an exploratory sleep add-on (REM “corridor”) with separate inclusion criteria. Importantly, null and equivalence results are reported as central outcomes, not secondary omissions, underscoring the falsifiability of the framework. This paper reports the full protocol, preregistration, results, (...) null distributions, and implications for falsifiability in cognitive and symbolic systems. Stage-1 denotes the first preregistered baseline test of ENT, not universality. -/- Emergent Necessity Theory (ENT) is a structural framework that proposes coherence in complex systems emerges as a necessity once containment forces (synchrony) and dispersive forces (entropy) reach a measurable balance. Its central object is the coherence ratio τ = S/(D+ε), a domain-agnostic, falsifiable metric. (shrink)

The quantum measurement problem, particularly the observer effect, has long resisted a complete explanation, often forcing a choice between paradoxical interpretations and a fundamental split between the quantum and classical worlds. This paper introduces Aethic reasoning, a novel framework that resolves the measurement problem by reformulating the logical and relational structure that underpins reality. We propose three foundational postulates that redefine realism, superposition, and state validity from a relational standpoint. The derivation begins with the Third Postulate, which posits that reality (...) is governed by a logical “checkmate” rule that invalidates any state where, in every possible future, a path to a contradiction persists. We demonstrate how this single constraint—a universe that tirelessly avoids paradox—logically necessitates the relational framework of the First Postulate, where realism is defined relative to an observer's informational state, or Aethus. Building on this, the Second Postulate, in conjunction with the Extrusion and Union Principles, provides a mechanism for defining superposition as a direct consequence of unknowable information. Together, these postulates form a cohesive system that yields a direct, step-by-step derivation of the double-slit experiment's outcomes. Aethic reasoning thus offers a robust and logically consistent solution to the quantum observer effect, unifying quantum and classical phenomena without introducing new physical entities or paradoxes. (shrink)

Breaking the Cosmogenesis Paradox: We propose a radical ontology where vacuum is fundamentally composed of closed-loop faster-than-light (FTL) potential energy strings—Meta Energy Loops (MELs)—that self-cancel to maintain net-zero energy. This substrate spontaneously generates reality through geometric symmetry breaking: -/- Particles emerge as localized loop slowdowns (vₗₒₒₚ ≤ c) -/- Spacetime arises recursively from loop transformation dynamics -/- Fundamental constants (α, mₑ, m_μ, m_τ) derive from twist topology -/- QED and GR unify at Λₗₒₒₚ = 10¹⁷ GeV via loop braiding -/- (...) Crucially, we derive: (i) Maxwell's equations from loop twist currents (ii) Particle mass hierarchy via winding quantization (iii) Gravitational lensing from time field compression (iv) Planck-scale blackbody radiation from thermal loop collapse -/- Testable predictions: (a) Frequency-dependent photon deflection Δv/c ∝ Eᵧ² (b) Exotic lepton at 12.6 ± 0.3 TeV (c) CMB y-distortion enhancement at z > 10⁶ -/- This framework resolves the "something from nothing" paradox through geometric recursion—without presupposing spacetime or quantum fields—while maintaining full compatibility with established physics. (shrink)

We refine how the Time Field Model (TFM) wave–lump interactions evolve from high-energy physics to chemical scales, providing explicit equations for orbital energy shifts, reaction-rate coherence effects, multi-atom PDE expansions, and HPC scalability. By treating nuclei and electrons as temporally resonant “wave-lumps” rather than static particles, we predict subtle deviations in atomic spectra, reaction kinetics, and molecular orbital energies. Preliminary HPC-optimized PDE solutions confirm bond stability and shell structure, offering a unified wave-based explanation of atomic orbitals, periodic trends, and chemical (...) reactivity. All figures (1–5) use mock data from HPC PDE solutions, mirroring early computational quantum chemistry. Future high-precision spectroscopy (e.g., Rydberg states) and ultra-cold reaction experiments may detect TFM’s ∼10⁻⁵ coherence effects, bridging fundamental physics and chemistry. (shrink)

This paper introduces a foundational model for reinterpreting quantum mechanics and temporality through the lens of recursive coherence and fluid dynamics. Rejecting the traditional notion of time and measurement as artificial constructs, I posit both arise from structural perturbations within a coherence substrate, a dynamic field of recursively stable potential. Quantum superposition is reframed as a fluid coherence state, wherein measurement corresponds to a localized phase transition that temporarily crystallizes into an observable particle. Once the perturbation subsides, the system reverts (...) to fluidic superposition. Time is not a universal axis but a measure of persistence within this coherence field, manifesting as the rate at which structural gradients evolve or dissolve. This model subsumes the measurement problem, collapses the necessity of Many-Worlds branching, and redefines probability as a coherence-weighted metric rather than fundamental indeterminacy. Drawing from prior work in Adaptive Quantum Coherence and Temporal Impermanence, this framework presents a unified substrate from which both time and quantum states emerge, governed by a single recursive evolution principle. The result is a theory that aligns information, entropy, and observation under coherent dynamics of frozen fluidity. (shrink)

This work introduces a novel model of quantum entities as physical, spatially extended wavefields, forming the basis for a realist framework for quantum measurement and collapse. Unlike interpretations that postulate hidden variables, observer-induced effects, ad hoc stochastic elements, or multiverse branching, this model derives the Born rule as a consequence of local physical interactions—involving kinetic energy transfer at or above a threshold—acting on an extended wavefield. Central to the model is a reinterpretation of the Heisenberg uncertainty principle—not as a statistical (...) or epistemic limitation, but as a dynamical relation between kinetic energy transfer and wavefield contraction. This framework yields testable predictions about how weak, intermediate, and strong quantum interactions modulate spatial localization—predictions consistent with existing experimental findings. The upshot is a unified, falsifiable alternative to prevailing interpretations, and a foundation for a broader research program in wavefield interaction mechanics. (shrink)

In recent years, I have proposed "Quantum Language (QL)" as a linguistic Copenhagen interpretation of quantum mechanics. This theory is applicable to both quantum and classical systems. Furthermore, I consider QL to be the scientific culmination of Western philosophical history. As a result, QL transforms the significance of almost all philosophical fields. In this paper, I demonstrate how the traditional evaluation of the Leibniz-Clarke correspondence is significantly altered through the lens of QL.

I consider whether the discovery of the quantum of action has any bearing on reductive physicalism. More particularly, I consider the arguments of the "new hylomorphists" to the effect that quantum physics sits most comfortably in their anti-reductionist framework.

The centered Everett interpretation solves a problem that various approaches to quantum theory face. In this paper, I continue developing the theory underlying that solution. In particular, I defend the centered Everett interpretation against a few objections, and I provide additional motivation for some of its key features.

The mistake of quantum physics relying on classical physics with its concept of reality confined to mas and space. The mistake of viewing the photon as a particle. The mistake of ignoring the latent identities of entities.

We propose the Prototime Interpretation of quantum mechanics, which claims that quantum entanglement occurs in a "prototemporal" realm which underlies spacetime. Our paper is tentative and exploratory. The argument form is inference to the best explanation. We claim that the Prototime Interpretation (PI) is worthy of further consideration as a superior explanation for perplexing quantum phenomena such as delayed choice, superposition, the wave-particle duality and nonlocality. In Section One, we introduce the Prototime Interpretation. Section Two identifies its advantages. Section Three (...) discusses several implications of the view, such as its deterministic nature and relation to the simulation hypothesis. (shrink)

It is impossible to have a noun without a verb (an entity without a process) (the arithmetic number ‘one’ without the arithmetic number ‘two’). This is why and how humans are amiss, currently, about ‘quantum’ circuits… (the entity and process humans identify as 'mind').

For scientific realists, quantum mechanics is unsatisfactory because it suffers from the measurement problem. However, there are at least three promising solutions: the pilot-wave theory, the many-worlds theory, and the theory of spontaneous collapse. In this paper I argue that the measurement problem is a false problem for the realist: it was proposed as the last resort to convince the positivists that the theory is not empirically adequate. Instead realists should focus on preserving the reductive explanatory schema that had worked (...) so well in physics before, which requires a theory to have a three-dimensional ontology. Incompleteness argument to this effect have been proposed in the 1920s, but effectively ignored due to the positivistic climate, other unscientific reasons, and theorems which claimed that this project was impossible. When realists re-examined quantum mechanics in the 1950s and later, they happened to focus on the measurement problem. In this paper I speculate on what would have happened if realists instead focused on finding a three-dimensional ontology to complete quantum theory. I show that most paradoxes, puzzles and mysteries connected with quantum mechanics would have never emerge, and that many of what are now considered possible ontological interpretations of the theory would have hardly been taken as viable options. (shrink)

This article aims to read feminist new materialisms (Barad), together with ‘postulated’ linguistic or cultural primacy of Queer Theory (Butler), to show how both are engaged in similar critical-ethical endeavours. The central argument is that the criticism of Barad and new materialisms misses Butler’s materialistic insights due to a narrow interpretation of Butler's alleged social-constructivist position. There is, therefore, a specific focus on where they both make similar ethical appeals. Moreover, the article relies on Adorno's negative dialectic to highlight an (...) interpretation of Barad and Butler as being part of the same dialectical movement, in which materialism and idealism fluctuate in their mutual criticisms, thus continuing the procession towards 'new knowledge' and emancipation, or freedom, through their motions back and forth. (shrink)

The problem of time involves an overlap between physics, philosophy, psychology and neuroscience. My talk will discuss the role of time in physics but also emphasize that physics may need to expand to address issues usually regarded as being in the other domains. I will first review the mainstream physics view of time, as it arises in Newtonian theory, relativity theory and quantum theory. I will then discuss the various arrows of time, the most fundamental of which is the passage (...) of time associated with consciousness. I will argue that this goes beyond both relativity theory and quantum theory, so that one needs some new physical paradigm to accommodate it. A new paradigm is required anyway to describe quantum gravity and this may elucidate the nature of both time and consciousness. (shrink)

It is argued that those who defend the Everett, or ‘many-worlds’, interpretation of quantum mechanics should embrace what we call the general quantum theory of open systems (GT) as the proper framework in which to conduct foundational and philosophical investigations in quantum physics. GT is a wider dynamical framework than its alternative, standard quantum theory (ST). This is true even though GT makes no modifications to the quantum formalism. GT rather takes a different view, what we call the open systems (...) view, of the formalism; i.e., in GT, the dynamics of systems whose physical states are fundamentally represented by density operators are represented as fundamentally open as specified by an in general non-unitary dynamical map. This includes, in principle, the dynamics of the universe as a whole. We argue that the more general dynamics describable in GT can be physically motivated, that there is as much prima facie empirical support for GT as there is for ST, and that GT could be fully in the spirit of the Everett interpretation—that there might, in short, be little reason for an Everettian not to embrace the more general theoretical landscape that GT allows one to explore. (shrink)

The main ideas of the EDWs perspective are in Gabriel Vacariu’s PhD thesis posted online by UNSW (Australia) in 2007!!! I have realized the GREATEST discovery in the history of human knowledge: the EDWs! With discovering the EDWs, I have changed everything in Philosophy, Physics and Cognitive Neuroscience! This has been the main reason, so many people have published UNBELIEVABLE similar ideas to my ideas, many years I published my first works! -/- UNBELIEVABLE, many (hundreds) “great” or small thinkers did (...) the same thing in 2006-2007 and later: they published the same ideas, UNBELIEVABLE similar to my ideas from 2002-2005! They believe they would be considered co-authors of the same new framework of thinking. They did not know that many “professors” would do the same thing: they plagiarized my ideas and they hurry up to published their work as soon as possible (in 2006-2007, depending when they discovered my article 2005). So, in the same 2 years, many people “discovered” the same new framework of thinking, the EDWs perspective, each of them did not think that there would be so many other people doing the same thing, that is, many people “discovered” the same new framework (the greatest challenge in the history of human thinking!) in the same period! Such coincidences (the discovery of the EDWs in the same two years!!!) are quite IMPOSSIBLE!! This is the reason nobody quoted my name, but nobody quoted any name who PLAGIARIZED my ideas… In 2006-2007, I was wondering why nobody quote my name, but in fact, they plagiarized my ideas. Nobody discovered this framework of thinking 2500 years, and in 2-3 years, many people discovered it!!!! IMPOSSIBLE!!!! There were some "professors" who published articles/chapters very close to Bohr's complementarity, Dirac, de Broglie's dualism before 2005 (for instance Carlo Rovelli 1996 or Ladyman), but their works were constructed within the "unicorn world" (Universe/world), therefore, these works had nothing in common with the EDWs perspective!!!! In reality, all of them plagiarized my ideas! It was like many people composed Beethoven Fifth’s Symphony, claiming that they never listen Beethoven! Who would be so stupid to believe them? (shrink)

The paper discusses this year’s Nobel Prize in physics for experiments of entanglement “establishing the violation of Bell inequalities and pioneering quantum information science” in a much wider, including philosophical context legitimizing by the authority of the Nobel Prize a new scientific area out of “classical” quantum mechanics relevant to Pauli’s “particle” paradigm of energy conservation and thus to the Standard model obeying it. One justifies the eventual future theory of quantum gravitation as belonging to the newly established quantum information (...) science. Entanglement, involving non-Hermitian operators for its rigorous description, non-unitarity as well as nonlocal and superluminal physical signals “spookily” (by Einstein’s flowery epithet) synchronizing and transferring some nonzero action at a distance, can be considered to be quantum gravity so that its local counterpart to be Einstein’s gravitation according to general relativity therefore pioneering an alternative pathway to quantum gravitation different from the “secondary quantization” of the Standard model. So, the experiments of entanglement once they have been awarded by the Nobel Prize launch particularly the relevant theory of quantum gravitation grounded on “quantum information science” thus granted to be nonclassical quantum mechanics in the shared framework of the generalized quantum mechanics obeying rather quantum-information conservation than only energy conservation. The concept of “dark phase” of the universe naturally linked to the very well confirmed “dark matter” and “dark energy” and opposed to its “light phase” inherent to classical quantum mechanics and the Standard model obeys quantum-information conservation, after which reversible causality or the mutual transformation of energy and information are valid. The mythical Big Bang after which energy conservation holds universally is to be replaced by an omnipresent and omnitemporal medium of decoherence of the dark and nonlocal phase into the light and local phase. The former is only an integral image of the latter and borrowed in fact rather from religion than from science. Physical, methodological and proper philosophical conclusions follow from that paradigm shift heralded by this year’s Nobel Prize in physics. For example, the scientific theory of thinking should originate from the dark phase of the universe, as well: probably only approximately modeled by neural networks physically belonging to the light phase thoroughly. A few crucial philosophical sequences follow from the break of Pauli’s paradigm: (1) the establishment of the “dark” phase of the universe as opposed to its “light” phase, only to which the Cartesian dichotomy of “body” and “mind” is valid; (2) quantum information conservation as relevant to the dark phase, furthermore generalizing energy conservation as to its light phase, productively allowing for physical entities to appear “ex nihilo”, i.e., from the dark phase, in which energy and time are yet inseparable from each other; (3) reversible causality as inherent to the dark phase; (4) the interpretation of gravitation only mathematically: as an interpretation of the incompleteness of finiteness to infinity, for example, following the Gödel dichotomy (“either contradiction or incompleteness”) about the relation of arithmetic to set theory; (5) the restriction of the concept of hierarchy only to the light phase; (6) the commensurability of both physical extremes of a quantum and the universe as a whole in the dark phase obeying quantum information conservation and akin to Nicholas of Cusa’s philosophical and theological worldview. (shrink)

This paper argues that every quantum system can be understood as a sufficiently general kind of stochastic process unfolding in an old-fashioned configuration space according to ordinary notions of probability. This argument is based on an exact correspondence between the class of “indivisible” stochastic processes and quantum theory. This new stochastic-quantum correspondence demotes the wave function from a primary ontological ingredient to a secondary mathematical tool and yields a deflationary account of exotic quantum phenomena, such as interference, decoherence, entanglement, noncommutative (...) observables, and wave-function collapse. At a more practical level, the stochastic-quantum correspondence leads to a novel reconstruction of quantum theory, alongside the Hilbert-space, path-integral, and quasiprobability representations, and also provides a framework for using Hilbert-space methods to formulate highly generic, non-Markovian types of stochastic dynamics, with potential applications throughout the sciences. (shrink)

We present a historical study of Quantum Technology 2.0 using more than 66,000 papers from 1980 to 2020 that had been assigned to four subfields. We applied the method reference publication year spectroscopy to respective publication sets of the subfields in order to identify their historical roots and seminal papers. We found 126 of them in total, 43 in quantum metrology and sensing, 46 in quantum communication and cryptography, 42 in quantum computing, and 33 in quantum information science–with a significant (...) overlap between subfields–which are all discussed in their relevance for the respective subfield. We compared the subfields regarding their interrelationship and distinctiveness in terms of their most influential papers and were able to deduce a common core set of five seminal publications in all four subfields. (shrink)

Time-symmetric formulation of quantum mechanics—the two-state vector formalism—is presented as a tool for studying past behaviour of quantum systems. A role of weak measurement and weak values in the Cheshire Cat effect and a nested (Vaidman) three-path interferometer are discussed. Interpretation of a particle’s faint trace indicating possibility of discontinuous paths of particles passing the Vaidman interferometer is given. Consistent histories are presented as one of alternative approaches. Multitude of controversial issues is briefly reviewed and discussed.

It has been argued that measurement-induced collapses in Orthodox Quantum Mechanics generates an intrinsic (or built-in) quantum arrow of time. In this paper, I critically assess this proposal. I begin by distinguishing between an intrinsic and non-intrinsic arrow of time. After presenting the proposal of a collapse-based arrow of time in some detail, I argue, first, that any quantum arrow of time in Orthodox Quantum Mechanics is non-intrinsic since it depends on external information about the measurement context, and second, that (...) it cannot be global, but just local. I complement these arguments by assessing some criticisms and considerations about the implementation of time reversal in contexts wherein measurement-induced collapses work. I conclude that the quantum arrow of time delivered by Orthodox Quantum Mechanics is much weaker than usually thought. (shrink)

A common discussion in philosophy of physics is about the realism vs instrumentalism debate on the nature of fields. We analyze the similarities and conceptual differences between quantum fields and the concept of Aristotelian materia prima, regarding the properties of intrinsic indeterminacy and its relation with forms. This leads to a different point of view of the realistic conceptions of fields, since this identification allows a realistic interpretation, but with the restriction of being incomplete entities.

Quantum theory offers mathematical descriptions of measurable phenomena with great facility and accuracy, but it provides absolutely no understanding of why any particular quantum outcome is observed. It is the province of genuine explanations to tell us how things actually work—that is, why such descriptions hold and why such predictions are true. Quantum theory is long on the what, both mathematically and observationally, but almost completely silent on the how and the why. What is even more interesting is that, in (...) some sense, this state of affairs seems to be a necessary consequence of the empirical adequacy of quantum descriptions. One of the most noteworthy achievements of quantum theory is the accurate prediction of phenomena that, on pain of experimental contradiction, have no physical explanation. It is the purpose of this essay to make clear why quantum mechanics and quantum field theory are complete physical descriptions that describe the metaphysical incompleteness of the physical world, then to press the negative implications of this fact for naturalistic metaphysics. (shrink)

This book presents fresh insights into analogue quantum simulation. It argues that these simulations are a new instrument of science. They require a bespoke philosophical analysis, sensitive to both the similarities to and the differences with conventional scientific practices such as analogical argument, experimentation, and classical simulation. -/- The analysis situates the various forms of analogue quantum simulation on the methodological map of modern science. In doing so, it clarifies the functions that analogue quantum simulation serves in scientific practice. To (...) this end, the authors introduce a number of important terminological distinctions. They establish that analogue quantum ‘computation' and ‘emulation' are distinct scientific practices and lead to distinct forms of scientific understanding. The authors also demonstrate the normative value of the computation vs. emulation distinction at both an epistemic and a pragmatic level. -/- The volume features a range of detailed case studies focusing on: i) cold atom computation of many-body localisation and the Higgs mode; ii) photonic emulation of quantum effects in biological systems; and iii) emulation of Hawking radiation in dispersive optical media. Overall, readers will discover a normative framework to isolate and support the goals of scientists undertaking analogue quantum simulation and emulation. This framework will prove useful to both working scientists and philosophers of science interested in cutting-edge scientific practice. (shrink)

The many worlds interpretation of quantum mechanics (MWI) states that the world we live in is just one among many parallel worlds. It is widely believed that because of this commitment to parallel worlds, the MWI violates common sense. Some go so far as to reject the MWI on this basis. This is despite its myriad of advantages to physics (e.g. consistency with relativity theory, mathematical simplicity, realism, determinism, etc.). Here, we make the case that common sense in fact favors (...) the MWI. We argue that causal explanations are commonsensical only when they are local causal explanations. We present several quantum mechanical experiments that seem to exhibit nonlocal “action at a distance”. Under the assumption that only one world exists, these experiments seem immune to local causal explanation. However, we show that the MWI, by taking all worlds together, can provide local causal explanations of the experiments. The MWI therefore restores common sense to physical explanation. (shrink)

This thesis develops a detailed account of the emergence of for all practical purposes continuous, quasi-classical world histories from the discontinuous, stochastic micro dynamics of Minimal Bohmian Mechanics (MBM). MBM is a non-relativistic quantum theory. It results from excising the guiding equation from standard Bohmian Mechanics (BM) and reinterpreting the quantum equilibrium hypothesis as a stochastic guidance law for the random actualization of configurations of Bohmian particles. On MBM, there are no continuous trajectories linking up individual configurations. Instead, individual configurations (...) are actualized independently of each other, carving out the decoherence-induced branching structure of the universal wave function. Yet, by contrast to the Everett interpretation, branches of the universal wave function are not actualized in parallel, i.e. all at the same time. Rather, world branches, on MBM, are actualized sequentially. -/- For an introduction to MBM, the transition from BM to MBM is described, and their empirical equivalence is established. I present the conditions under which MBM can be classified as a primitive ontology (PO) theory, regarded as crucial for the acceptance of a theory as Bohmian by many proponents of BM. While rendering MBM compatible with the PO approach, it must not fall prey to the problem of communication, arising from the two-space reading of BM. -/- The issue of temporal solipsism, identified by Bell as a serious problem for his “Everett (?) theory” – the historic predecessor of MBM – is discussed. I argue that Barbour’s time capsule approach does not provide a satisfactory solution. In particular, his adopting a more than minimal psychophysical parallelism between brain processes and experience of macroscopic change is argued to be reasonable in light of our current best neuroscience, yet problematic for theories relying solely on time capsules, understood as highly structured, individual, internally static configurations. As a solution, I introduce worlds, and world histories, as key concepts in providing a link between MBM’s micro dynamics and macroscopic phenomena. Worlds, other than time capsules, are coarse-grained regions in phase- or configuration space, defined as sets of possible micro states satisfying a relation of sufficient similarity from a macroscopic perspective, with respect to a given micro state. Hence, worlds may overlap. -/- I argue that worlds thus construed are a reasonable option for replacing the disjoint macro regions of phase space, resulting from the usual way of partitioning phase space in the standard framework of Boltzmannian statistical mechanics. This move solves the issue of discontinuous change of macro variables upon the micro state crossing the boundary between different macro regions. -/- I adapt this move for MBM’s discontinuous micro dynamics in configuration space. Issues revolving around the microscopic-macroscopic distinction, particle identity, impenetrability and haecceity in light of the desideratum of particle number conservation, etc., are discussed. I provide a detailed explanation of how overlapping worlds in MBM form world histories, thereby linking up macroscopically distinct worlds. Thus, the problem of temporal solipsism is resolved in a way that is compatible with a more than minimal psychophysical parallelism. (shrink)

This paper surveys the status of scientific realism in relation to quantum physics, focusing on the problem of underdetermination.

Econophysics is a branch of economics that applies concepts and methods from physics to the financial markets. This article focuses on the approaches to quantum finance developed by Kirill Ilinski and Belal E. Baaquie to deal with the uncertainty characterizing financial time series. Allegedly, their models rest on a formal analogy between quantum mechanics and finance. In order to evaluate them, we raise the question what is really quantum in quantum econophysics. We then argue that the supposed analogy breaks in (...) an important manner, which is relevant to explain the empirical success of the proposed models. (shrink)

A recent no-go theorem gives an extension of the Wigner’s Friend argument that purports to prove the “Quantum theory cannot consistently describe the use of itself.” The argument is complex and thought provoking, but fails in a straightforward way if one treats QM as a statistical theory in the most fundamental sense, i.e. if one applies the so-called ensemble interpretation. This explanation is given here at an undergraduate level, which can be edifying for experts and students alike. A recent paper (...) has already shown that the no-go theorem is incorrect with regard to the de Broglie Bohm theory and misguided in some of its general claims. This paper’s contribution is three fold. It shows how the extended Wigner’s Friend argument fails in the ensemble interpretation. It also makes more evident how natural a consistent statistical treatment of the wave function is. In this way, the refutation of the argument is useful for bringing out the core statistical nature of QM. It, in addition, manifests the unnecessary complications and problems introduced by the collapse mechanism that is part of the Copenhagen interpretation. The paper uses the straightforwardness of the ensemble interpretation to make the no-go argument and its refutation more accessible. (shrink)

Remote state preparation is generation of a desired state by a remote observer. In spite of causality, it is well known, according to the Reeh–Schlieder theorem, that it is possible for relativistic quantum field theories, and a “physical” process achieving this task, involving superoscillatory functions, has recently been introduced. In this work we deal with non-relativistic fields, and show that remote state preparation is also possible for them, hence obtaining a Reeh–Schlieder-like result for general fields. Interestingly, in the nonrelativistic case, (...) the process may rely on completely different resources than the ones used in the relativistic case. (shrink)

This study examines quaternion Dirac solutions for an infinite square well. The quaternion result does not recover the complex result within a particular limit. This raises the possibility that quaternionic quantum mechanics may not be understood as a correction to complex quantum mechanics, but it may also be a structure that can be used to study phenomena that cannot be described through the framework of complex quantum mechanics.

We study Bell inequalities and EPR states in the context of Jordan algebras. We show that the set of states violating Bell inequalities across two operator commuting nonmodular Jordan Banach algebras is norm dense in the global state space. It generalizes hitherto known results in quantum field theory in several directions. We propose new Jordan quantity for incommensurable observables in a given state, introduce the concept of EPR state for Jordan structures, and study relationship between EPR states and Bell correlated (...) states. Our analysis shows crucial role of spin factors and Pauli spin matrices for studying noncommutative properties of states and observables. (shrink)

Those looking for holism in contemporary physics have focused their attention primarily on quantum entanglement. But some gauge theories arguably also manifest the related phenomenon of nonseparability. While the argument is strong for the classical gauge theory describing electromagnetic interactions with quantum “particles”, it fails in the case of general relativity even though that theory may also be formulated in terms of a connection on a principal fiber bundle. Anandan has highlighted the key difference in his analysis of a supposed (...) gravitational analog to the Aharonov-Bohm effect. By contrast with electromagnetism in the original Aharonov-Bohm effect, gravitation is separable and exhibits no novel holism in this case. Whether the nonseparability of classical gauge theories of non-gravitational interactions is associated with holism depends on what counts as the relevant part-whole relation. Loop representations of quantized gauge theories of non- gravitational interactions suggest that these conclusions about holism and nonseparability may extend also to quantum theories of the associated fields. (shrink)

Quantum information science is a source of task-related axioms whose consequences can be explored in general settings encompassing quantum mechanics, classical theory, and more. Quantum states are compendia of probabilities for the outcomes of possible operations we may perform on a system: ''operational states.'' I discuss general frameworks for ''operational theories'' (sets of possible operational states of a system), in which convexity plays key role. The main technical content of the paper is in a theorem that any such theory naturally (...) gives rise to a ''weak effect algebra'' when outcomes having the same probability in all states are identified and in the introduction of a notion of ''operation algebra'' that also takes account of sequential and conditional operations. Such frameworks are appropriate for investigating what things look like from an ''inside view,'' i.e., for describing perspectival information that one subsystem of the world can have about another. Understanding how such views can combine, and whether an overall ''geometric'' picture (''outside view'') coordinating them all can be had, even if this picture is very different in structure from the perspectives within it, is the key to whether we may be able to achieve a unified, ''objective'' physical view in which quantum mechanics is the appropriate description for certain perspectives, or whether quantum mechanics is truly telling us we must go beyond this ''geometric'' conception of physics. (shrink)

The simplest case of quantum field theory on curved spacetime—that of the Klein–Gordon field on a globally hyperbolic spacetime—reveals a dilemma: In generic circumstances, either there is no dynamics for this quantum field, or else there is a dynamics that is not unitarily implementable. We do not try to resolve the dilemma here, but endeavour to spell out the consequences of seizing one or the other horn of the dilemma.

We give an accurate historical and scientific account of a practically unknown manuscript written by Ettore Majorana in French. The retrieved text deals with Quantum Electrodynamics by using the formalism of field quantization, and it is here reported, for the first time, in English translation. It is likely related to an invited talk for a conference at Leningrad in 1933 which, however, Majorana never attended. Probably this manuscript is one of the last missing papers of the “Senatore folder,” given by (...) Majorana to one student of his at the University of Naples in 1938, just before his disappearance. (shrink)

It has been suggested in the literature that spatial coherence of the wave function can be dynamically suppressed by fluctuations in the spacetime geometry. These fluctuations represent the minimal uncertainty that is present when one probes spacetime geometry with a quantum probe. Two similar models have been proposed, one by Diósi and one by Karolyhazy and collaborators, based on apparently unrelated minimal spacetime bounds. The two models arrive at somewhat different expressions for the dependence of the localization coherence length on (...) the mass and size of the quantum object. In the present article we compare and contrast the two models from three aspects: comparison of the spacetime bounds, method of calculating decoherence time, comparison of noise correlation. We show that under certain conditions the minimal spacetime bounds in the two models can be derived one from the other. We argue that the methods of calculating the decoherence time are equivalent. We re-derive the two-point correlation for the fluctuation potential in the K-model, and confirm the earlier result of Diósi and Lukács that it is non-white noise, unlike in the D-model, where the corresponding correlation is white noise in time. This seems to be the origin of the different results in the two models. We derive the non-Markovian master equation for the K-model. We argue that the minimal spacetime bound cannot predict the noise correlation uniquely, and additional criteria are necessary to accurately determine the effects of gravitationally induced decoherence. (shrink)

A century after the advent of quantum mechanics and general relativity, both theories enjoy incredible empirical success, constituting the cornerstones of modern physics. Yet, paradoxically, they suffer from deep-rooted, so-far intractable, conflicts. Motivations for violations of the notion of relativistic locality include the Bell’s inequalities for hidden variable theories, the cosmological horizon problem, and Lorentz-violating approaches to quantum geometrodynamics, such as Horava–Lifshitz gravity. Here, we explore a recent proposal for a “real ensemble” non-local description of quantum mechanics, in which “particles” (...) can copy each others’ observable values AND phases, independent of their spatial separation. We first specify the exact theory, ensuring that it is consistent and has quantum mechanics as a fixed point, where all particles with the same values for a given observable have the same phases. We then study the stability of this fixed point numerically, and analytically, for simple models. We provide evidence that most systems are locally stable to small deviations from quantum mechanics, and furthermore, the phase variance per value of the observable, as well as systematic deviations from quantum mechanics, decay as \ time)\, where \. Interestingly, this convergence is controlled by the absolute value of energy, suggesting a possible connection to gravitational physics. Finally, we discuss different issues related to this theory, as well as potential novel applications for the spectrum of primordial cosmological perturbations and the cosmological constant problem. (shrink)

We consider the special and general relativistic extensions of the action principle behind the Schrödinger equation distinguishing classical and quantum contributions. Postulating a particular quantum correction to the source term in the classical Einstein equation we identify the conformal content of the above action and obtain classical gravitation for massive particles, but with a cosmological term representing off-mass-shell contribution to the energy–momentum tensor. In this scenario the—on the Planck scale surprisingly small—cosmological constant stems from quantum bound states having a Bohr (...) radius a as being \. (shrink)