This Element offers an introduction to selected philosophical issues that arise in contemporary particle physics, aimed at philosophers who have limited prior exposure to quantum field theory. One the one hand, it critically surveys philosophical work on the representation of particles in quantum field theory, the formal machinery and conceptual implications of renormalization and renormalization group methods, and ontological and methodological questions raised by the use of effective field theory techniques in particle physics. On the other, it identifies (...) topics in particle physics that have not yet received philosophical attention and sketches avenues for philosophical analysis of those topics. The primary aim of the Element is to provide philosophers of physics with an entry point into the literature on the philosophy of particle physics and identify interesting directions for future research for students and researchers alike. (shrink)

This paper establishes that particle ontology is logically unnecessary in fundamental physics. The dimensionless invariant ξ ≡ μα — product of the proton-to-electron mass ratio μ and the fine-structure constant α — cancels all particle-ontological prerequisites through dependence annihilation, yielding a purely spectral quantity. While μ and α individually presuppose particle ontology, their product ξ² = (μα)² resides in the kernel of the scale-valuation map, constituting the unique minimal generator of scale-invariant spectral observables of M₃(ℂ). This is (...) not a numerical coincidence but a structural consequence of axioms A1 (non-commutativity) and A2 (metric completeness). The natural variable ξ² admits a closed-form six-term expansion derived exclusively from axioms A1–A3 of Cognitional Mechanics, with zero free parameters. The numerical value ξ² = 179.5347... agrees with experiment to within 1.73×10⁻¹³ (relative). Once ξ² is constructively realized from the algebra, retaining particle taxonomy as a primitive becomes structurally untenable: the declaration of phlogiston-equivalence is a logical necessity imposed by the algebra itself, not a philosophical preference. All gauge-invariant observables of the Standard Model reduce to spectral data of Spec(D) on the algebra A_F = M₃(ℂ) ⊕ ℂ. The surjective map ℰ: S_spec → T_SM and the Reconstruction Lemma establish that ξ² is a complete gauge-invariant statistic for the observational content of the Standard Model. Asymptotic freedom, DGLAP phenomenology, and three-generation structure are accounted for as Tier-2 projections of M₃(ℂ) without particle ontology. Particle ontology satisfies all three phlogiston-equivalence criteria and is structurally redundant. -/- Published on April 25, 2026 doi: 10.5281/zenodo.19753339. (shrink)

Chemical bonding has been defined, since the early twentieth century, in terms of electron sharing and Coulombic interaction between charged particles. This definition presupposes particle ontology at every level. Cognitional Mechanics (CM) establishes that particles are not ontological primitives but Tier-3 projections of Tier-2 spectral structure generated by the unique minimal non-commutative algebra M₃(ℂ). Once particle ontology is eliminated — as demonstrated in the companion paper "Particles Are Unnecessary" (DOI: 10.5281/zenodo.18810386) — the standard definition of chemical bonding becomes (...) logically unavailable. A definition built on Tier-3 artifacts cannot serve as a foundational account of Tier-2 structure without circularity. -/- This paper provides the necessary reconstruction. Chemical bonding is redefined as a spectral resonance condition between two M₃(ℂ) operational domains, governed by the chemical projection constant n_A = 36 derived from Axiom A2 alone. The spectral coupling constant ξ ≡ μα — the unique Tier-1 composite in which particle-ontological prerequisites cancel — connects the mass-hierarchy and electromagnetic projections of M₃(ℂ) to the chemical energy scale without invoking particle concepts. Bond energy ratios between molecular species are parameter-free, falsifiable Tier-1 predictions derived from the A3 cyclotomic invariants Φ₃ = 13 and Φ₆ = 7. Absolute energy scales remain Tier-3 quantities requiring empirical calibration; this is a structural consequence of the Tier architecture, not a limitation. The periodic table admits a spectral reordering, developed in the companion paper on chemical periodicity, in which the anomalies of the particle-indexed arrangement are dissolved as projection artifacts. (shrink)

This paper introduces the Topological Unified Field Theory (TUFT), a unified framework formulated on the complex Hopf fibration. We prove that any unified gauge theory whose U(1) sector satisfies charge quantization (discrete admissible charges) and completeness (realization of every principal U(1)-bundle over any paracompact base) must be formulated, up to homotopy equivalence of the base and isomorphism of bundles, on the universal complex Hopf fibration S^1 --> S^inf --> CP^inf and its finite approximations S^1 --> S^(2n+1) --> CP^n. Such a (...) system is shown to be indecomposable, in the sense that it presents as a unified field which cannot be decomposed without loss of information. The Standard Model gauge groups arise as natural reductions along a nested shell hierarchy: U(1) from the circular S^1 fiber, SU(2) from the S^3 shell, and SU(3) from the S^5 shell. The classifying spaces BU(1), BSU(2), and BSU(3) are all internal to this single hierarchy; each is obtained by changing the quotient on the same universal total space S^inf, not by independent construction. Gravity emerges as the spacetime gauge sector from the Kahler geometry of the base together with fiber-induced torsion, yielding a structure analogous to Einstein-Cartan theory, with the Levi-Civita connection recovered in the torsion-free limit. The unified structure group G_total = (SU(3) x SU(2) x U(1) x SO(4))/Gamma is intrinsically non-factorable due to the generating role of the universal first Chern class in H*(CP^inf; Z) = Z[c_1]. The unique universal action on the Hopf bundle is derived from SO(4)-equivariance, the Killing form, and degree classification; the torsion action is the unique admissible positive-definite quadratic form. The Einstein, Maxwell, and Yang-Mills field equations all follow from this single action. The Beltrami operator B = *d|_xi on the contact distribution is doubly forced as both the action Hessian and the unique equivariant first-order operator. The result is a topologically enhanced Standard Model: every term of the conventional SM Lagrangian appears with identical structure, with no free parameters, and with gravity via Chern-Simons theory on S^3, the Beltrami mass operator, and the resolution of the strong CP problem as enhancements. Gravity emerges on the S^3 = SU(2) shell, sharing exactly one generator -- the Cartan U(1) -- with the gauge sector; gauge-gravity unification is the fibration U(1) --> SU(2) itself. On each Hopf shell, the generalized Beltrami operator B = d|_xi acting on the contact distribution is elliptic, essentially self-adjoint, and possesses a discrete spectrum stable under torsion perturbations by the Kato-Rellich theorem. Fiber winding decomposition yields independent topological sectors whose Gaussian functional determinants, regularized via spectral zeta functions, generate intrinsic mass scales. Fermion mixing (CKM, PMNS) arises from intersection-form overlaps of admissible cycles in H(CP^4), with CP violation induced by fiber holonomy phases. Dynamics emerge from the fluctuation spectrum of the topological action on S^9. Given a single empirical input scale set by the Fermi constant (with its associated electroweak vacuum expectation value), the fine-structure constant and all shell-specific mass scales, spectral coefficients, and coupling constants are determined by the spectral geometry of the complex Hopf fibration. The framework predicts the full particle mass spectrum and anomalous magnetic moments, and proposes independent experimental tests, including torsion-induced phase wobble, the absolute neutrino mass scale, and precision measurements of the electron, muon, and tau g-2, providing clear routes to falsifiability. Fundamental constants arise from topological normalization. Additional consequences include anomaly cancellation, dark sector effects from bundle torsion and holonomy, and the elimination of singularities. Independently of physical interpretation, the results contribute to the topology of classifying spaces, reductions along nested Hopf fibrations, and contact spectral geometry. This paper has been in a rigorous, stringent peer review upon invitation of the International Journal of Topology, an applied topology journal in collaboration with the journal Mathematics, with Editor-in-Chief Michel Planat (a quantum gravity theorist). The paper has passed 4 rounds of peer review and is currently in Round 5 for revision for publication. (IF YOU USE THIS PAPER IN YOUR RESEARCH CITE THIS PAPER!!!!!). (shrink)

In this paper I put forward a new micro realistic, fundamentally probabilistic, propensiton version of quantum theory. According to this theory, the entities of the quantum domain - electrons, photons, atoms - are neither particles nor fields, but a new kind of fundamentally probabilistic entity, the propensiton - entities which interact with one another probabilistically. This version of quantum theory leaves the Schroedinger equation unchanged, but reinterprets it to specify how propensitons evolve when no probabilistic transitions occur. Probabilisitic transitions occur (...) when new "particles" are created as a result of inelastic interactions. All measurements are just special cases of this. This propensiton version of quantum theory, I argue, solves the wave/particle dilemma, is free of conceptual problems that plague orthodox quantum theory, recovers all the empirical success of orthodox quantum theory, and at the same time yields as yet untested predictions that differ from those of orthodox quantum theory. (shrink)

The procedures of validating computer simulations of particle physicsParticle physics events at the LHCLarge Hadron Collider are summarized. Because of the strongly fluctuating particle content of LHC events and detectorDetector interactions, particle-based Monte Carlo methods are an indispensable tool for dataData analysis analysis. Simulation in particle physicsParticle physics is founded on factorizationFactorization and thus its global validation can be realized by validating each individual step in the simulation. This can be accomplished by drawing on results of (...) previousMeasurement measurements, in situ studies, and models. What is particularly important in particle physicsParticle physics is to quantify how well a simulation is validated such that a systematic uncertainty can be assigned to a measurement. The simulation is tested for a wide range of processes and agrees with dataData within the assigned uncertainties. (shrink)

The major point in [1] chapter 2 is the following claim: “Any formalized system for the Theory of Computation based on Classical Logic and Turing Model of Computation leads us to a contradiction.” So, in the case we wish to save Classical Logic we should change our Computational Model. As we see in chapter two, the mentioned contradiction is about and around the concept of time, as it is in the contradiction of modified version of paradox. It is natural to (...) try fabricating the paradox not by time but in some other linear ordering or the concept of space. Interestingly, the attempts to have similar contradiction by the other concepts like space and linear ordering, is failed. It is remarkable that, the paradox is considered either Epistemological or Logical traditionally, but by new considerations the new version of paradox should be considered as either Logical or Physical paradox. Hence, in order to change our Computational Model, it is natural to change the concept of time, but how? We start from some models that are different from the classical one but they are intuitively plausible. The idea of model is somewhat introduced by Brouwer and Husserl [3]. This model doesn’t refute the paradox, since the paradox and the associated contradiction would be repeated in this new model. The model is introduced in [2]. Here we give some more explanations. (shrink)

In this work we discuss issues of ontological commitment towards one of the most important examples of contemporary fundamental science: the standard model of particle physics. We present a new form of selective structural realism, which uses as its basis the distinction between what have been called framework and interaction theories. This allows us to advance the ongoing debate about the ontological status of (quasi-)particles and quantum fields, by emphasising the distinction between quantum field theory serving as a framework, (...) and the standard model itself, which we argue is an interaction theory embedded within this framework. Following a discussion of what ontological commitments corresponds to each of these two classes, we argue that some of the previous proposals in the literature might have been misguided by the blending of quantum field theory and the standard model into an undifferentiated unity, and defend a moderate form of object realism with respect to particle-like entities. (shrink)

The operation of fundamental forces in quantum field theory is explicated here as the exchange of particles, consistently with the standard methodology of particle physics. The particles involved are seen to bear little relation to any classical particle but, rather, comprise unified collections of compresent, conserved quantities indicated by propagators. The exchange particles, which supervene upon quantum fields, are neither more fundamental than fields nor replace them as has often previously been assumed in models of exchange forces. It (...) is argued that this explication of quantum field-theoretic exchange forces definitively improves upon its predecessors. (shrink)

This paper initiates a fundamental ontological shift in the physical sciences. We argue that the Standard Model, despite its predictive success, has fallen into a "category error" inherited from 20th-century nuclear chemistry: the pursuit of ever-smaller material constituents. Much like Ptolemaic astronomy, which maintained accuracy through the accumulation of arbitrary epicycles, the Standard Model relies on 19 free parameters and ad hoc mechanisms (such as the Higgs field) that lack structural necessity. -/- Within the framework of Cognitional Mechanics (CM), we (...) propose an "Operational Ontology" where the category of "physical existence" is restricted to stable eigenvalue clusters observable at the chemical scale. All sub-nuclear phenomena—quarks, gluons, and gauge bosons—are reconceived not as material "things," but as internal modes of a minimal non-commutative algebra: M3(C) ⊕ C. -/- By applying the Spectral Action Principle to this internal structure, we derive gravity, gauge interactions, nucleon mass generation, atomic structure, and the periodic table without introducing any particle as an ontological primitive. Neutrinos are identified as spacetime eigenmodes (Layer III) coupled to Riemannian curvature, yielding a derived mass scale and a specific curvature coupling (ξ = −1/6) without requiring right-handed neutrinos. -/- Published: February 28, 2026. DOI: 10.5281/zenodo.18810386. (shrink)

Einstein claimed that the fundamental dynamical insight of special relativity was the equivalence of mass and energy. I disagree. Not only are mass and energy not equivalent but talk of such equivalence obscures the real dynamical insight of special relativity, which concerns the nature of 4-forces and interactions more generally. In this paper I present and defend a new ontology of special relativistic particle dynamics that makes this insight perspicuous and I explain how alleged cases of mass–energy conversion can (...) be accommodated within that ontology. (shrink)

The assertion that an experiment by Afshar et al. demonstrates violation of Bohr’s Principle of Complementarity is based on the faulty assumption that which-way information in a double-slit interference experiment can be retroactively determined from a future measurement.

It is argued that the high degree of trust in the Higgs particle before its discovery raises the question of a Bayesian perspective on data analysis in high energy physics in an interesting way that differs from other suggestions regarding the deployment of Bayesian strategies in the field.

I consider the idea of a structure of fundamental physical particles being causal. Causation is traditionally thought of as involving relations between entities—objects or events—that cause and are affected. On structuralist interpretations, however, it is unclear whether or how precisely fundamental particles can be causally efficacious. On some interpretations, only relations exist; on others, particles are ontologically dependent on their relations in ways that problematize the traditional picture. I argue that thinking about causal efficacy in this context generates an inevitable (...) pattern of reasoning. To assess the cogency of a given structuralist proposal one must take a stand with respect to a significant metaphysical challenge. Two options then emerge: skepticism about the form of structuralism at issue; or a dissolution of the challenge by means of a contentious ontological primitive. I contend that the choice between these options cannot be forced on scientific or philosophical grounds alone. (shrink)

This paper critically explores how ‘chemicals at the nanoscale’ are defined under the Australian Industrial Chemicals Introduction Scheme (AICIS) and compares it with the definitions established by the United States Environmental Protection Agency (US EPA) and European Commission (EC). Focusing on the properties of particle size and solubility, it explores how Australian regulators have translated the underlying nanoscience into their formal definitional framework. It then considers the regulatory implications that may arise from the application of Australia’s specific interpretation. This (...) study reveals significant differences in how particle size and solubility are applied within nanomaterial definitions. AICIS structures its definitional framework around these physical properties as regulatory proxies for material risk, relying heavily on archetypal behaviours and characteristics that may not apply universally across all substances. In contrast, American and European frameworks more explicitly recognize these criteria have limited predictive capability for risk assessment and have designed frameworks that allow regulators greater flexibility in identifying and assessing nanoscale chemicals. In application, AICIS’ more simplified approach creates a narrower regulatory scope that may poorly correspond with toxicological outcomes. This has direct implications for which substances are included or excluded from more stringent regulatory oversight. Future legal research should subsequently explore how AICIS’ definition is applied in practice, focusing on how regulators pursue enforcement actions for materials that challenge these regulatory parameters. (shrink)

This volume brings together eleven essays by the distinguished philosopher of science, Peter Achinstein. The unifying theme is the nature of the philosophical problems surrounding the postulation of unobservable entities such as light waves, molecules, and electrons. How, if at all, is it possible to confirm scientific hypotheses about "unobservables"? Achinstein examines this question as it arose in actual scientific practice in three nineteenth-century episodes: the debate between particle and wave theorists of light, Maxwell's kinetic theory of gases, and (...) J.J. Thomson's discovery of the electron. The book contains three parts, each devoted to one of these topics, beginning with an essay presenting the historical background of the episode and an introduction to the philosophical issues. There is an illuminating evaluation of various scientific methodologies, including hypothetico-deductivism, inductivism, and the method of independent warrant which combines features of the first two. Achinstein assesses the philosophical validity of both nineteenth-century and modern answers to questions about unobservables, and presents and defends his own solutions. (shrink)

While scientific realism generally assumes that successful scientific explanations yield information about reality, realists also have to admit that not all information acquired in this way is equally well warranted. Some versions of scientific realism do this by saying that explanatory posits with which we have established some kind of causal contact are better warranted than those that merely appear in theoretical hypotheses. I first explicate this distinction by considering some general criteria that permit us to distinguish causal warrant from (...) theoretical warrant. I then apply these criteria to a specific case from particle physics, claiming that scientific realism has to incorporate the distinction between causal and theoretical warrant if it is to be an adequate stance in the philosophy of particle physics. (shrink)

The success of particle detection in high energy physics colliders critically depends on the criteria for selecting a small number of interactions from an overwhelming number that occur in the detector. It also depends on the selection of the exact data to be analyzed and the techniques of analysis. The introduction of automation into the detection process has traded the direct involvement of the physicist at each stage of selection and analysis for the efficient handling of vast amounts of (...) data. This tradeoff, in combination with the organizational changes in laboratories of increasing size and complexity, has resulted in automated and semi-automated systems of detection. Various aspects of the semi-automated regime were greatly diminished in more generic automated systems, but turned out to be essential to a number of surprising discoveries of anomalous processes that led to theoretical breakthroughs, notably the establishment of the Standard Model of particle physics. The automated systems are much more efficient in confirming specific hypothesis in narrow energy domains than in performing broad exploratory searches. Thus, in the main, detection processes relying excessively on automation are more likely to miss potential anomalies and impede potential theoretical advances. I suggest that putting substantially more effort into the study of electron–positron colliders and increasing its funding could minimize the likelihood of missing potential anomalies, because detection in such an environment can be handled by the semi-automated regime—unlike detection in hadron colliders. Despite virtually unavoidable excessive reliance on automated detection in hadron colliders, their development has been deemed a priority because they can operate at currently highest energy levels. I suggest, however, that a focus on collisions at the highest achievable energy levels diverts funds from searches for potential anomalies overlooked due to tradeoffs at the previous energy thresholds. I also note that even in the same collision environment, different research strategies will opt for different tradeoffs and thus achieve different experimental outcomes. Finally, I briefly discuss current searches for anomalous process in the context of the previous analysis. (shrink)

We critically review the recent debate between Doreen Fraser and David Wallace on the interpretation of quantum field theory, with the aim of identifying where the core of the disagreement lies. We show that, despite appearances, their conflict does not concern the existence of particles or the occurrence of unitarily inequivalent representations. Instead, the dispute ultimately turns on the very definition of what a quantum field theory is. We further illustrate the fundamental differences between the two approaches by comparing them (...) both to the Bohmian program in quantum field theory. (shrink)

Among physicists and cosmologists, it is common practice to refer to the "cosmic laboratory" to describe how the study of the universe others important insights into the inner constitution of matter. Yakov Zel'dovich, for instance, famously claimed that the "universe is the poor man's accelerator." The goal of this paper is to clarify the relationship between cosmology and particle physics by examining a case of crucial importance in connecting these fields: how cosmologists of the 1970s were able to limit (...) the number of lepton families from the measure of the cosmic abundance of helium-4 . My claim is that knowledge of the primordial universe enables cosmologists to conceive it as a natural experiment for testing hypotheses of particle physics, thereby supporting the analogy between the universe and particle colliders. (shrink)

It is usually stated that quantum mechanics presents problems with the identity of particles, the most radical position—supported by E. Schrödinger—asserting that elementary particles are not individuals. But the subject goes deeper, and it is even possible to obtain states with an undefined particle number. In this work we present a set theoretical framework for the description of undefined particle number states in quantum mechanics which provides a precise logical meaning for this notion. This construction goes in the (...) line of solving a problem posed by Y. Manin, namely, to incorporate quantum mechanical notions at the foundations of mathematics. We also show that our system is capable of representing quantum superpositions. (shrink)

Current theories of consciousness explain how physical activity gives rise to conscious experience. They do not explain why a particular first-person perspective remains attached to one physical system rather than another. Thought experiments involving brain reactivation, reconstruction, and replication expose this gap: physical and psychological duplication does not specify which resulting system, if any, carries forward the original subjective viewpoint. This article treats that gap as a distinct explanatory target and develops a candidate account, the two-particle model, built from (...) two functionally distinct hypothetical entities: X-UQUPC, proposed to confer identity persistence, and X-UQGPC, proposed to mediate bidirectional interaction between mental states and neural activity. I state the logical constraints the model must satisfy and give the strongest available alternative accounts a fair hearing, including deflationary, functionalist, and predictive-processing views. I then propose two experiments designed to discriminate the model from theories that treat consciousness as fully constituted by current computational or informational organization (Global Neuronal Workspace Theory, Integrated Information Theory, Higher-Order Theory, and predictive processing), and state plainly that no experiment can discriminate the model from Orchestrated Objective Reduction or test its core claim about which of several structurally identical systems, if any, continues a given perspective, since that claim is unobservable by construction rather than merely difficult to measure. For each remaining prediction I specify the expected observation, the leading conventional alternative explanation, the controls needed to distinguish them, and the criteria for support or falsification, without assigning numerical values the model cannot justify. The model’s value does not depend on it being correct; it depends on whether it can be tested and, if tested, shown to be wrong. (shrink)

In this article, I address concerns that the ontological priority claims definitive of ontic structural realism are as they stand unclear, and I do so by placing these claims on a more rigorous formal footing than they typically have been hitherto. I first of all argue that Kit Fine’s analysis of ontological dependence furnishes us with an ontological priority relation that is particularly apt for structuralism. With that in place, and with reference to two case studies prominent within the structuralist (...) literature, I consider whether any of structuralism’s distinctive priority claims may be regarded as warranted. The discussion as a whole has largely negative implications for the radical structuralism of French and Ladyman (including their ‘eliminativist’ interpretation of it), largely positive implications for the moderate structuralism primarily advocated by Esfeld and Lam, and some broad lessons for contemporary fundamentalist metaphysics as a whole. 1 Introduction2 The Right Priority Relation for Structuralism: Supervenience or Dependence?3 Introducing Ontological Dependence4 Fine’s System5 The Priority of Structure 1: Entangled Quantum Particles6 The Priority of Structure 2: The Group-Theoretic Conception of Elementary Particles7 Concluding Remarks. (shrink)

Summary Some case studies in elementary particle physics are presented in this work, that can be used for the critical appraisal of specific criteria which were proposed to account for the development of Heisenberg's work. It is attempted to define the philosophical problems associated with and emerging from the structures of theories, rather than analyse the philosophical aspects of concepts used in elementary particle physics. This necessitates the discussion of the relationship between theory and experiment, and the role (...) of the mathematical framework being used. The question of elementarity is studied in this connection. Popper's tetradic schema and his concept of world three are modified, and it is shown that the new schema can accommodate the development of certain research programs in a much more satisfactory manner. As a result of the systematic treatment of specific research programs, the principle of contextual re-interpretation is expanded by specifying the different kinds of interpretations at the various stages of development of theories. It is also shown that principles such as those of simplicity and beauty can be understood in terms of the mathematical structure of the theories, and their methodological importance is emphasized. (shrink)

The formulation of quantum mechanics developed by Bohm, which can generate well-defined trajectories for the underlying particles in the theory, can equally well be applied to relativistic quantum field theories to generate dynamics for the underlying fields. However, it does not produce trajectories for the particles associated with these fields. Bell has shown that an extension of Bohm’s approach can be used to provide dynamics for the fermionic occupation numbers in a relativistic quantum field theory. In the present paper, Bell’s (...) formulation is adopted and elaborated on, with a full account of all technical detail required to apply his approach to a bosonic quantum field theory on a lattice. This allows an explicit computation of trajectories for massive and massless particles in this theory. Also particle creation and annihilation, and their impact on particle propagation, is illustrated using this model. (shrink)

Ocean biology helps regulate global climate by fixing atmospheric CO2 and exporting it to deep waters as sinking detrital particles. New observations demonstrate that particle fragmentation is the principal factor controlling the depth to which these particles penetrate the ocean's interior, and hence how long the constituent carbon is sequestered from the atmosphere. The underlying cause is, however, poorly understood. We speculate that small, particle‐associated copepods, which intercept and inadvertently break up sinking particles as they search for attached (...) protistan prey, are the principle agents of fragmentation in the ocean. We explore this idea using a new marine ecosystem model. Results indicate that explicitly representing particle fragmentation by copepods in biogeochemical models offers a step change in our ability to understand the future evolution of biologically‐mediated ocean carbon storage. Our findings highlight the need for improved understanding of the distribution, abundance, ecology and physiology of particle‐associated copepods. (shrink)

According to structural realism, in mature science there is structural continuity along theoretical change. A major counterexample to this thesis is the transition from the Eightfold Way to the Standard Model in particle physics. Nevertheless, the notion of structure is significantly important in comprehending the theoretical picture of particle physics, where particles change and undergo transmutations, while the only thing which remains unchanged is the basic structure, i.e. the symmetry group which controls the transmutations. This kind of view (...) agrees with the paradigmatic case where the structure is an internal symmetry and the instantiations are the elementary particles. The metaphysical view which reflects this situation is a version of ontic structuralism. (shrink)

Effective and personalized treatment relies heavily on skin disease categorization. In the stratification of skin disorders, it is crucial to identify the subtypes of illnesses to provide an efficient therapy. To attain this aim, researchers have focused their attention on cluster algorithms for the stratification of skin disorders in recent decades. But, cluster algorithms have real-world drawbacks, including experimental noises, a large number of dimensions, and a poor ability to comprehend. Cluster algorithms, in particular, determine the quality of clusters using (...) a single internal evaluation operation in the majority of cases. A single internal assessment procedure is difficult to design and robust for all datasets, which is a problem. The multi-objective particle swarm obtained high sensitivity in the existing work, but it is not able to anticipate all kinds of classes. An optimized cluster distance parameter for K-means clustering is determined using a hybrid particle swarm and moth flame optimization. Multi-objective is guided by two cluster value indices, including the K-means clustering misclassification rate and neural network classification rate. Hybrid PSO will solve the multi-objective problem to identify the optimal cluster for clustering. On the dermatological dataset from the UCI repository, MATLAB R2020a will be used to evaluate the proposed method. This will be followed by an evaluation of the proposed method’s performance using the cluster evaluation indices. (shrink)

Recently, Clifton and Halvorson have tried to salvage a particle phenomenology in the absence of particle ontology within algebraic relativistic quantum field theory. Their idea is that the detection of a particle is the measurement of a local observable which simulates the measurement of an almost local observable that annihilates the vacuum. In this note, we argue that the measurements local particle detections are supposed to simulate probe radically holistic aspects of relativistic quantum fields. We prove (...) that in an axiomatic (Haag-Araki) quantum field theory on Minkowski spacetime, formulated in a Hilbert space $\mathcal{H}$, there is no positive observable C, with norm less than or equal to 1, satisfying the conditions: (1) the expectation value of C in the vacuum state Ω is zero, (2) there is at least one vector state Ψ in $\mathcal{H}$ in which the expectation value of C is different from zero, and (3) there exists at least one spacetime region $\mathcal{O}$ such that the non-selective measurement of C leaves the expectation values of all observables in the local algebra of that region unaltered regardless of the state the system is in. The result reveals a tension between intuitions regarding localization and intuitions regarding causality: to save “particle phenomena” in the absence of particle ontology, one has to feign “particle” detectors with “good” properties as to locality but “bad” behavior as to causality. (shrink)

In his paper ``What is Structural Realism?'' James Ladyman drew a distinction between epistemological structural realism and metaphysical (or ontic) structural realism. He also drew a suggestive analogy between the perennial debate between substantivalist and relationalist interpretations of spacetime on the one hand, and the debate about whether quantum mechanics treats identical particles as individuals or as `non-individuals' on the other. In both cases, Ladyman's suggestion is that an ontic structural realist interpretation of the physics might be just what is (...) needed to overcome the stalemate. The main thesis of this paper is that, whatever the interpretative difficulties of generally covariant spacetime physics are, they do not support or suggest structural realism. In particular, I hope to show that there is in fact no analogy that supports a similar interpretation of the metaphysics of spacetime points and of quantum particles. (shrink)

: This work proposes the methodology to obtain a correlation between the particle size of the rock material and the point load test index, in order to characterize the materials, present in mining projects in terms of resistance. For a correct development of mining activities, both open pit and underground, it is important to determine the compressive strength of the rocks, since, through it, geomechanical classifications are obtained, and thus calculate safety factors to define stabilization and/or fortification systems for (...) mining operations. This work was developed on the basis of samples from a geological formation and subsequent preparation of specimens, then they were subjected to physical tests, which can be carried out without problem in the field, and finally, the respective relationships were obtained. The results are encouraging and the equations are proposed to characterize the rock and achieve the proposed objective. Keywords: Rock, Crushing, Classification, Compression. (shrink)

Problems with the conceptual foundations of quantum mechanics date back to attempts by Max Born, Niels Bohr, Werner Heisenberg, as well as many others in the 1920s to continue to employ the classical concept of a particle in the context of the quantum world. The experimental observations at the time and the assumption that the classical concept of a particle was to be preserved have led to an enormous literature on the foundations of quantum mechanics and a great (...) deal of confusion then and now among non-physicists and students in any field that involves quantum theory. It is the historical approach to the teaching of quantum mechanics that is at the root of the problem. Spacetime is the arena within which quantum mechanical phenomena take place. For this reason, several Appendices are devoted to the nature of spacetime as well as to topics that can help us understand it such as vacuum fluctuations, the Unruh effect and Hawking radiation. Because of the success of quantum mechanical calculations, those who wish to understand the foundations of the theory are often given the apocryphal advice, "just ignore the issue and calculate". It is hoped that this book will help dispel some of the dismay, frustration, and confusion among those who refuse to take to heart this admonition. (shrink)

The machines exhibit an intelligence which is artificial intelligence, and it is the design of intelligent agents. A system is represented by an intelligent agent who perceives its environment and the success rate is maximized by taking the action. The AI research is highly specialized and there are two subfields and each communication fails often. The popular AI approaches include the traditional symbolic AI and computational intelligence. In order to optimize the seismic design of the reinforced concrete pier structure, the (...) particle swarm optimization algorithm and the reaction spectrum analysis method are combined; they establish a regular bridge of the design variable with cross-sectional characteristics and reinforcement ratios, with the target function. The seismic optimization design framework of the pier is transformed into a multi-objective optimization problem. Calculations show that the method can quickly obtain the optimal design parameters that meet multi-objective requirements. The improved PSO main program and the calling push-over program run time are 4.32 and 1347.56 s, respectively; the push-over program running time is 99.68% of the run time of the total program. Optimization of the seismic performance of the rear bridge pier is significantly improved and is more in line with the design method; the design method proposed in this article is more practical. (shrink)

In order to solve the shortcomings of particle swarm optimization in solving multiobjective optimization problems, an improved multiobjective particle swarm optimization algorithm is proposed. In this study, the competitive strategy was introduced into the construction process of Pareto external archives to speed up the search process of nondominated solutions, thereby increasing the speed of the establishment of Pareto external archives. In addition, the descending order of crowding distance method is used to limit the size of external archives and (...) dynamically adjust particle parameters; in order to solve the problem of insufficient population diversity in the later stage of algorithm iteration, time-varying Gaussian mutation strategy is used to mutate the particles in external archives to improve diversity. The simulation experiment results show that the improved algorithm has better convergence and stability than the other compared algorithms. (shrink)

The mathematical rules used to handle systems of identical quantum particles bring into question whether the elementary constituents of matter, such as electrons, have the fundamental characteristics of persistence and reidentifiability that are usually attributed to classical particles. However, despite considerable philosophical debate, the metaphysical profile of these entities remains elusive. -/- Previous debates have taken the mathematical rules, and the language in which these are usually couched, as a starting point. Here, we argue that this methodology is inherently limited, (...) and develop a new conception of identical particles based on a recent mathematical reconstruction of these rules. Using this reconstruction, we demonstrate that the special behaviour of identical particles originates in the confluence of identicality and the active nature of the quantum measurements. We propose that identical particles are appropriately viewed as potential parts of a whole, and show how this leads to striking consequences such as restricted transtemporal identity. (shrink)

I argue against the currently prevalent view that algebraic quantum field theory (AQFT) is the correct framework for philosophy of quantum field theory and that “conventional” quantum field theory (CQFT), of the sort used in mainstream particle physics, is not suitable for foundational study. In doing so, I defend that position that AQFT and CQFT should be understood as rival programs to resolve the mathematical and physical pathologies of renormalization theory, and that CQFT has succeeded in this task and (...) AQFT has failed. I also defend CQFT from recent criticisms made by Doreen Fraser. (shrink)

In this short article I discuss the variae lectiones in Il. 8.408 and 8.422. All manuscripts have ὅττι νοήσω (408) and ὅττι νοήσῃ (422), but many editors have preferred to print Aristarkhos’ corrections ὅττί κεν εἴπω and ὅττί κεν εἴπῃ respectively. By comparing the instances in which ὅττί κεν εἴπω/ῃς/ῃ and ὅττι νοήσω/ῃς/ῃ are used and by delving deeper into the use of the modal particle (MP) in epic Greek, I argue that the transmitted readings ὅττι νοήσω (408) and (...) ὅττι νοήσῃ (422) should have preference, because they have no MP and refer to repeated actions, whereas the construction ὅττί κεν εἴπω/ῃς/ῃ, which has an MP, refers to a more specific instance (which is why it has an MP in the first place). (shrink)

Further arguments are offered in defence of the position that the variant of quantum field theory (QFT) that should be subject to interpretation and foundational analysis is axiomatic quantum field theory. I argue that the successful application of renormalization group (RG) methods within alternative formulations of QFT illuminates the empirical content of QFT, but not the theoretical content. RG methods corroborate the point of view that QFT is a case of the underdetermination of theory by empirical evidence. I also urge (...) caution in extrapolating interpretive conclusions about QFT from the application of RG methods in other contexts (e.g., condensed matter physics). This paper replies to criticisms advanced by David Wallace, but aims to be self-contained. (shrink)

The paper explains response particles like yes and no as anaphoric elements that pick up propositional discourse referents that are introduced by preceding sentences. It is argued that negated antecedent clauses introduce two propositional discourse referents, which results in ambiguities of answers that are partly resolved by pragmatic optimization. The paper also discusses response particles like okay, right, uh-huh, uh-uh, and German ja, nein and doch.

A coordinate-free formulation is established for (semi) classical particle-field interactions. The exterior language of spacetime chains and De-Rham currents enables the description to include extended strings and membranes besides point particles. Treating physical fields in terms of sections of particular bundles, a unified account of interactions is presented in terms of an intrinsic action principle on a bundle of jets over spacetime. The theory is illustrated by considering the specific model of point particles with intrinsic spin covariantly coupled to (...) theU(1) andSL(2, C) connections describing the electromagnetic and gravitational fields, respectively. The notion of dual spin is examined in this context and coupled equations for this particle-field system are explicitly derived in a local chart. Attention is drawn to the global implications of the theory. (shrink)

I. Egner, “The role of topos in the use of a Wobe particle”.In the paper I am trying to show how a speaker using the particle {ie271-1} in his utterance calls upon a contextual assumption that can be formulated as a topos.After formulating a working hypothesis according to which the particle {ie271-2} signals to the hearer that the speaker's utterance is justified, I use English and Wobe paraphrases of the examples quoted in order to make explicit that (...) justification.Wobe paraphrases given by the informant suggest that in using {ie271-3} the speaker calls upon t contextual assumption that he feels is relevant in the speech situation. To the extent that this assumption is based on common sense knowledge, it seemed appropriate to use Ducrot's notion of topos to formulate it, e.g. (T) [The deeper one gets into the bush, the fewer white people he meets].One of the examples quoted calls attention to the fact that the topos called upon by way of {ie271-4} may or may not be validated, i.e. confirmed in the speech situation.Finally, the validation or non-validation of a topos seems to determine the illocutionary value of a wh-question containing {ie271-5} as request for information or request for explanation respectively. (192 words). (shrink)

The Hamilton–Jacobi (HJ) equation for the action function plays a fundamental role in classical mechanics. A known consequence of the HJ equation is a blow-up of a disturbed free-particle solution. Following the idea of Sivashinsky, we formulate an extension of the HJ equation in which perturbations eventually evolve into a finite autosoliton associated with an elementary particle. A novel element of the model is stability of the autosoliton. We link uncertainties in the position and momentum of a (...) class='Hi'>particle to a width and amplitude of the autosoliton. We formulate restrictions on the coefficients of the model and compare the model with some existing theories of extended elementary objects. (shrink)

The symmetrization postulates of quantum mechanics (symmetry for bosons, antisymmetry for fermions) are usually taken to entail that quantum particles of the same kind (e.g., electrons) are all in exactly the same state and therefore indistinguishable in the strongest possible sense. These symmetrization postulates possess a general validity that survives the classical limit, and the conclusion seems therefore unavoidable that even classical particles of the same kind must all be in the same state—in clear conflict with what we know about (...) classical particles. In this article we analyze the origin of this paradox. We shall argue that in the classical limit classical particles emerge, as new entities that do not correspond to the “particle indices” defined in quantum mechanics. Put differently, we show that the quantum mechanical symmetrization postulates do not pertain to particles, as we know them from classical physics, but rather to indices that have a merely formal significance. This conclusion raises the question of whether many discussions in the literature about the status of identical quantum particles have not been misguided. (shrink)

The chapter argues: (1) that Achinstein's construal of theory testing requires both an enumeration, and a systematic refutation, of all possible alternatives to a hypothesis ostensibly under test. Such a demand is generally unrealizable; (2) that his epistemic dismissal of the corroboratory power of confirmed, surprising predictions is at odds with the methods advocated and utilized by most of the principal actors in the wave-particle debates of the nineteenth century; and (3) that his postulate of a shared methodological (and (...) Bayesian) consensus between corpuscularians and undulationists ignores the fact that the wave–particle debate was simultaneously an epistemic controversy about the virtues that an acceptable theory should exhibit. (shrink)

We suggest that spin and particle number are more naturally associated with the generators of a group than are spin and mass value (as is usually assumed). This is examined using the hypercomplex number formalism of relativistic physics.

The consensus view among philosophers of physics is that relativistic quantum field theory does not describe particles. That is, according to QFT, particles are not fundamental entities. How is this negative conclusion compatible with the positive role that the particle notion plays in particle physics? The first part of this chapter lays out multiple lines of negative argument that all conclude that QFT cannot be given a particle interpretation. These arguments probe the properties of the `particles' in (...) standard formulations of QFT and the limited applicability of `particle' representations. The second part of the chapter surveys proposals for non-fundamental roles that the particle concept plays in particle physics. The conclusion suggests directions for future philosophical research. (shrink)