Svoboda | Graniru | BBC Russia | Golosameriki | Facebook
 
 
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (23)

Search Parameters:
Keywords = worldline

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
24 pages, 316 KiB  
Article
A Field-Theory Approach for Modeling Dissipative Relativistic Fluids
by Nils Andersson, Thomas Celora, Gregory Comer and Ian Hawke
Entropy 2024, 26(8), 621; https://doi.org/10.3390/e26080621 - 24 Jul 2024
Viewed by 482
Abstract
We develop an action principle for producing a single-fluid two-constituent system with dissipation in general relativity. The two constituents in the model are particles and entropy. The particle flux creation rate is taken to be zero, while the entropy creation rate is non-zero. [...] Read more.
We develop an action principle for producing a single-fluid two-constituent system with dissipation in general relativity. The two constituents in the model are particles and entropy. The particle flux creation rate is taken to be zero, while the entropy creation rate is non-zero. Building on previous work, it is demonstrated that a new term (the proper time derivative of the matter space “metric”) is required in the Lagrangian in order to produce terms typically associated with bulk and shear viscosity. Equations of motion, entropy creation rate, and energy–momentum–stress tensor are derived. Using an Onsager approach of identifying thermodynamic “forces” and “fluxes”, a model is produced which delivers the same entropy creation rate as the standard, relativistic Navier–Stokes equations. This result is then contrasted with a model generated in the spirit of the action principle, which takes as its starting point a specific Lagrangian and then produces the equations of motion, entropy creation rate, and energy–momentum–stress tensor. Unlike the equations derived from Onsager reasoning, where the analogs of the bulk and shear viscosity coefficients are prescribed “externally”, we find that the forms of the coefficients in the second example are a direct result of the specified Lagrangian. Furthermore, the coefficients are shown to satisfy evolution equations along the fluid worldline, also a product of the specific Lagrangian. Full article
(This article belongs to the Section Statistical Physics)
16 pages, 331 KiB  
Article
Fractional Laplacian Spinning Particle in External Electromagnetic Field
by Claudio Maia Porto, Cresus Fonseca de Lima Godinho and Ion Vasile Vancea
Dynamics 2023, 3(4), 855-870; https://doi.org/10.3390/dynamics3040046 - 17 Dec 2023
Cited by 1 | Viewed by 729
Abstract
We construct a fractional Laplacian spinning particle model in an external electromagnetic field that generalizes a standard relativistic spinning particle model without anti-commuting spin variables. The one-dimensional fractional Laplacian in world-line variable λ governs the kinetic energy that is non-local in λ. [...] Read more.
We construct a fractional Laplacian spinning particle model in an external electromagnetic field that generalizes a standard relativistic spinning particle model without anti-commuting spin variables. The one-dimensional fractional Laplacian in world-line variable λ governs the kinetic energy that is non-local in λ. The interaction between the particle’s charge and the electromagnetic four-potential is non-local in λ, while the interaction between the particle’s spin tensor and the electromagnetic field is standard. By applying the variational principle, we obtain the equations of motion for particle coordinates. We solve analytically the equations of motion in two particular cases: the constant electric and magnetic field. For more complex field configurations, the equations are, in general, non-local and non-linear. By making the assumption of a much weaker interaction term between the charge and four-potential compared with the interaction between spinning degrees of freedom and the electromagnetic field, we obtain approximate analytical solutions in the case of a quadratic electromagnetic potential. Full article
14 pages, 398 KiB  
Article
Algebrodynamics: Shear-Free Null Congruences and New Types of Electromagnetic Fields
by Vladimir V. Kassandrov, Joseph A. Rizcallah and Ivan A. Matveev
Axioms 2023, 12(11), 1061; https://doi.org/10.3390/axioms12111061 - 20 Nov 2023
Viewed by 966
Abstract
We briefly present our version of noncommutative analysis over matrix algebras, the algebra of biquaternions (B) in particular. We demonstrate that any B-differentiable function gives rise to a null shear-free congruence (NSFC) on the B-vector space CM and [...] Read more.
We briefly present our version of noncommutative analysis over matrix algebras, the algebra of biquaternions (B) in particular. We demonstrate that any B-differentiable function gives rise to a null shear-free congruence (NSFC) on the B-vector space CM and on its Minkowski subspace M. Making use of the Kerr–Penrose correspondence between NSFC and twistor functions, we obtain the general solution to the equations of B-differentiability and demonstrate that the source of an NSFC is, generically, a world sheet of a string in CM. Any singular point, caustic of an NSFC, is located on the complex null cone of a point on the generating string. Further we describe symmetries and associated gauge and spinor fields, with two electromagnetic types among them. A number of familiar and novel examples of NSFC and their singular loci are described. Finally, we describe a conservative algebraic dynamics of a set of identical particles on the “Unique Worldline” and discuss the connections of the theory with the Feynman–Wheeler concept of “One-Electron Universe”. Full article
(This article belongs to the Special Issue Computational Mathematics and Mathematical Physics)
Show Figures

Figure 1

21 pages, 2427 KiB  
Article
Nonlocality, Superposition, and Time in the 4+1 Formalism
by Filip Strubbe
Entropy 2023, 25(11), 1493; https://doi.org/10.3390/e25111493 - 29 Oct 2023
Viewed by 1069
Abstract
The field of quantum gravity struggles with several problems related to time, quantum measurement, nonlocality, and realism. To address these issues, this study develops a 4+1 formalism featuring a flat 4D spacetime evolving with a second form of time, τ, worldlines that [...] Read more.
The field of quantum gravity struggles with several problems related to time, quantum measurement, nonlocality, and realism. To address these issues, this study develops a 4+1 formalism featuring a flat 4D spacetime evolving with a second form of time, τ, worldlines that locally conserve momentum, and a hypersurface representing the present. As a function of τ, worldlines can spatially readjust and influences can travel backward or forward in the time dimension along these worldlines, offering a physical mechanism for retrocausality. Three theoretical models are presented, elucidating how nonlocality in an EPR experiment, the arrival time problem, and superposition in a Mach–Zehnder interferometer can be understood within this 4+1 framework. These results demonstrate that essential quantum phenomena can be reproduced in the 4+1 formalism while upholding the principles of realism, locality, and determinism at a fundamental level. Additionally, there is no measurement or collapse problem, and a natural explanation for the quantum-to-classical transition is obtained. Furthermore, observations of a 4D block universe and of the flow of time can be simultaneously understood. With these properties, the presented 4+1 formalism lays an interesting foundation for a quantum gravity theory based on intuitive principles and compatible with our observation of time. Full article
(This article belongs to the Special Issue Time and Temporal Asymmetries)
Show Figures

Figure 1

16 pages, 430 KiB  
Article
Quantum Probabilities for the Causal Ordering of Events
by Charis Anastopoulos and Maria-Electra Plakitsi
Dynamics 2023, 3(4), 695-710; https://doi.org/10.3390/dynamics3040037 - 16 Oct 2023
Viewed by 1161
Abstract
We develop a new formalism for constructing probabilities associated with the causal ordering of events in quantum theory, where an event is defined as the emergence of a measurement record on a detector. We start with constructing probabilities for the causal ordering events [...] Read more.
We develop a new formalism for constructing probabilities associated with the causal ordering of events in quantum theory, where an event is defined as the emergence of a measurement record on a detector. We start with constructing probabilities for the causal ordering events in classical physics, where events are defined in terms of worldline coincidences. Then, we show how these notions generalize to quantum systems, where there exists no fundamental notion of trajectory. The probabilities constructed here are experimentally accessible, at least in principle. Our analysis here clarifies that the existence of quantum orderings of events do not require quantum gravity effects: it is a consequence of the quantum dynamics of matter, and it appears in the presence of a fixed background spacetime. Full article
Show Figures

Figure 1

30 pages, 2091 KiB  
Article
Local Quantum Theory with Fluids in Space-Time
by Mordecai Waegell
Quantum Rep. 2023, 5(1), 156-185; https://doi.org/10.3390/quantum5010011 - 21 Feb 2023
Cited by 4 | Viewed by 2031
Abstract
In 1948, Schwinger developed a local Lorentz-covariant formulation of relativistic quantum electrodynamics in space-time which is fundamentally inconsistent with any delocalized interpretation of quantum mechanics. An interpretation compatible with Schwinger’s theory is presented, which reproduces all of the standard empirical predictions of conventional [...] Read more.
In 1948, Schwinger developed a local Lorentz-covariant formulation of relativistic quantum electrodynamics in space-time which is fundamentally inconsistent with any delocalized interpretation of quantum mechanics. An interpretation compatible with Schwinger’s theory is presented, which reproduces all of the standard empirical predictions of conventional delocalized quantum theory in configuration space. This is an explicit, unambiguous, and Lorentz-covariant “local hidden variable theory” in space-time, whose existence proves definitively that such theories are possible. This does not conflict with Bell’s theorem because it is a local many-worlds theory. Each physical system is characterized by a wave-field, which is a set of indexed piece-wise single-particle wavefunctions in space-time, each with its own coefficient, along with a memory which contains the separate local Hilbert-space quantum state at each event in space-time. Each single-particle wavefunction of a fundamental system describes the motion of a portion of a conserved fluid in space-time, with the fluid decomposing into many classical point particles, each following a world-line and recording a local memory. Local interactions between two systems take the form of local boundary conditions between the differently indexed pieces of those systems’ wave-fields, with new indexes encoding each orthogonal outcome of the interaction. The general machinery is introduced, including the local mechanisms for entanglement and interference. The experience of collapse, Born rule probability, and environmental decoherence are discussed, and a number of illustrative examples are given. Full article
(This article belongs to the Special Issue The Many-Worlds Interpretation of Quantum Mechanics)
Show Figures

Figure 1

9 pages, 560 KiB  
Communication
Electron as a Tiny Mirror: Radiation from a Worldline with Asymptotic Inertia
by Michael R. R. Good and Yen Chin Ong
Physics 2023, 5(1), 131-139; https://doi.org/10.3390/physics5010010 - 28 Jan 2023
Cited by 6 | Viewed by 1822
Abstract
We present a moving mirror analog of the electron, whose worldline possesses asymptotic constant velocity with corresponding Bogoliubov β coefficients that are consistent with finite total emitted energy. Furthermore, the quantum analog model is in agreement with the total energy obtained by integrating [...] Read more.
We present a moving mirror analog of the electron, whose worldline possesses asymptotic constant velocity with corresponding Bogoliubov β coefficients that are consistent with finite total emitted energy. Furthermore, the quantum analog model is in agreement with the total energy obtained by integrating the classical Larmor power. Full article
(This article belongs to the Special Issue Vacuum Fluctuations)
Show Figures

Figure 1

17 pages, 6439 KiB  
Article
Single-Photon Double-Slit Interference in the 4+1 Formalism
by Filip Strubbe
Universe 2022, 8(10), 511; https://doi.org/10.3390/universe8100511 - 29 Sep 2022
Cited by 1 | Viewed by 1917
Abstract
Unifying quantum theory with general relativity is challenging because of several problems related to time and to collapse in quantum measurements. In the double-slit experiment, the questions are how the momentum of the photon is transferred to a specific location on the screen [...] Read more.
Unifying quantum theory with general relativity is challenging because of several problems related to time and to collapse in quantum measurements. In the double-slit experiment, the questions are how the momentum of the photon is transferred to a specific location on the screen and how the double slit recoils accordingly. This work investigates if these problems can be solved by adding a second time τ, which acts as an external evolution parameter, to standard four-dimensional spacetime. Within the resulting 4+1 formalism, a model for the single-photon double-slit experiment is developed. On the one hand, each spacetime associated to a value of τ relies on classical worldlines that obey local momentum conservation. On the other hand, these worldlines are allowed to readjust as a function of τ such that the quantum phenomenon of double-slit interference can be reproduced. The model explains how determinate outcomes are produced and how momentum transfer occurs in a way that satisfies the principles of relativity and local momentum conservation. As a result, the measurement problem and the problem of time evaporate, and an explanation for our experience of the present emerges. Since the presented model succeeds in explaining a key quantum phenomenon with essentially classical worldlines, this is relevant for the field of quantum gravity. Full article
(This article belongs to the Section Foundations of Quantum Mechanics and Quantum Gravity)
Show Figures

Graphical abstract

20 pages, 4536 KiB  
Article
Einstein’s Elevator: World Lines, Michelson–Morley Experiment and Relativistic Paradox
by Mathieu Rouaud
Physics 2022, 4(3), 892-911; https://doi.org/10.3390/physics4030058 - 11 Aug 2022
Viewed by 3256
Abstract
We all have in mind Einstein’s famous thought experiment in the elevator where we observe the free fall of a body, and then the trajectory of a light ray. Here, in addition to the qualitative aspect, the exact calculations are carried out, and [...] Read more.
We all have in mind Einstein’s famous thought experiment in the elevator where we observe the free fall of a body, and then the trajectory of a light ray. Here, in addition to the qualitative aspect, the exact calculations are carried out, and the worldlines equations are given. A uniformly accelerated reference frame in rectilinear translation is considered, and it is shown that the trajectories of the particles are semi-ellipses with the center on the event horizon. The frame of reference is non-inertial, the spacetime is flat, and the computations are performed within the framework of special relativity. Some experimental consequences are discussed, especially the experiment with the accelerated Michelson–Morley interferometer is solved, and an experiment, where a new relativistic paradox appears—a particle of matter seems to go faster than light—is described. The differences, compared to the classical case, are important at a large scale and close to the horizon, but they are small in the lift where the interest is above all theoretical. The concepts of metric, coordinated velocity and horizon are discussed, and an analogy with the black hole is made. Full article
(This article belongs to the Section Classical Physics)
Show Figures

Figure 1

18 pages, 1168 KiB  
Article
A Methodology for Generating Systems Architectural Glimpse Statements Using the 5W1H Maxim
by Orfefs Voutyras, Aamir H. Bokhari, Akira Tsuge, Georgios Palaiokrassas, Takafumi Kawasaki, Xavier Cases-Camats, Jin Nakazawa, Antonios Litke, Tadashi Okoshi and Theodora Varvarigou
Computers 2021, 10(10), 131; https://doi.org/10.3390/computers10100131 - 15 Oct 2021
Cited by 1 | Viewed by 3798
Abstract
Attempts to facilitate and streamline systems architecting have resulted in a great number of reusable principles, practices, mechanisms, frameworks, and tools. Such a practice is the use of architectural viewpoints and views. However, as systems change, these practices should also evolve. The increasing [...] Read more.
Attempts to facilitate and streamline systems architecting have resulted in a great number of reusable principles, practices, mechanisms, frameworks, and tools. Such a practice is the use of architectural viewpoints and views. However, as systems change, these practices should also evolve. The increasing scale and complexity of systems resulting from an ever-growing pool of human needs and breakthroughs may lead, in some cases, to an increased gap between the abstraction activities attempting to capture the whole of a system, and the instantiation activities that produce concrete and detailed descriptions of a system’s architecture. To address this issue, this article introduces a new notion, that of architectural glimpse statements, fundamental questions acting as the building blocks for architectural views and products. This notion can help architects ask the right questions in the right manner to create fundamental statements, the elaboration on which can lead directly to concrete architectural products. Working on top of standardized and common approaches, the article introduces a language for the creation of architectural glimpse statements using the 5W1H maxim. Based on this language, a tool and guidelines are also provided to facilitate the usage of glimpses. Finally, the overall methodology is demonstrated in two case studies. Full article
(This article belongs to the Section Internet of Things (IoT) and Industrial IoT)
Show Figures

Figure 1

1964 KiB  
Proceeding Paper
On Spacetime Duality and Bounce Cosmology of a Dual Universe
by Mohammed B. Al-Fadhli
Phys. Sci. Forum 2021, 2(1), 61; https://doi.org/10.3390/ECU2021-09291 - 22 Feb 2021
Viewed by 2242
Abstract
The recent Planck Legacy 2018 release confirmed the existence of an enhanced lensing amplitude in the cosmic microwave background (CMB) power spectra. Notably, this amplitude is higher than that estimated by the lambda cold dark matter model, which prefers a positively curved early [...] Read more.
The recent Planck Legacy 2018 release confirmed the existence of an enhanced lensing amplitude in the cosmic microwave background (CMB) power spectra. Notably, this amplitude is higher than that estimated by the lambda cold dark matter model, which prefers a positively curved early Universe with a confidence level greater than 99%. In this study, the pre-existing curvature is incorporated to extend the field equations where the space-time worldlines are utilised to model the evolution of the Universe with reference to the scale factor of the early Universe and its radius of curvature upon the emission of the CMB. The worldlines reveal both positive and negative solutions, implying that matter and antimatter of early Universe plasma evolved in opposite directions as distinct Universe sides during a first decelerating phase. The worldlines then indicate a second accelerated phase in reverse directions, whereby both sides free-fall towards each other under gravitational acceleration. The simulation of the predicted conformal curvature evolution demonstrates the fast orbital speed of the outer stars owing to external fields exerted on galaxies as they travel through conformally curved space-time. Finally, the worldlines predict an eventual time-reversal phase comprising rapid spatial contraction that culminates in a Big Crunch, signalling a cyclic Universe. These findings reveal that the early Universe’s plasma could be separated and evolved into distinct sides of the Universe that collectively and geometrically inducing its evolution, physically explaining the effects attributed to dark energy and dark matter. Full article
(This article belongs to the Proceedings of The 1st Electronic Conference on Universe)
Show Figures

Figure 1

18 pages, 312 KiB  
Article
Deconstructing Frame-Dragging
by Luis Herrera
Universe 2021, 7(2), 27; https://doi.org/10.3390/universe7020027 - 27 Jan 2021
Cited by 2 | Viewed by 2292
Abstract
The vorticity of world-lines of observers associated with the rotation of a massive body was reported by Lense and Thirring more than a century ago. In their example, the frame-dragging effect induced by the vorticity is directly (explicitly) related to the rotation of [...] Read more.
The vorticity of world-lines of observers associated with the rotation of a massive body was reported by Lense and Thirring more than a century ago. In their example, the frame-dragging effect induced by the vorticity is directly (explicitly) related to the rotation of the source. However, in many other cases, it is not so, and the origin of vorticity remains obscure and difficult to identify. Accordingly, in order to unravel this issue, and looking for the ultimate origin of vorticity associated to frame-dragging, we analyze in this manuscript very different scenarios where the frame-dragging effect is present. Specifically, we consider general vacuum stationary spacetimes, general electro-vacuum spacetimes, radiating electro-vacuum spacetimes, and Bondi–Sachs radiating spacetimes. We identify the physical quantities present in all these cases, which determine the vorticity and may legitimately be considered as responsible for the frame-dragging. Doing so, we provide a comprehensive, physical picture of frame-dragging. Some observational consequences of our results are discussed. Full article
(This article belongs to the Special Issue Frame-Dragging and Gravitomagnetism)
29 pages, 376 KiB  
Article
A 4+1 Formalism for the Evolving Stueckelberg-Horwitz-Piron Metric
by Martin Land
Symmetry 2020, 12(10), 1721; https://doi.org/10.3390/sym12101721 - 19 Oct 2020
Cited by 7 | Viewed by 1787
Abstract
We propose a field theory for the local metric in Stueckelberg–Horwitz–Piron (SHP) general relativity, a framework in which the evolution of classical four-dimensional (4D) worldlines xμτ (μ=0,1,2,3) is parameterized by an [...] Read more.
We propose a field theory for the local metric in Stueckelberg–Horwitz–Piron (SHP) general relativity, a framework in which the evolution of classical four-dimensional (4D) worldlines xμτ (μ=0,1,2,3) is parameterized by an external time τ. Combining insights from SHP electrodynamics and the ADM formalism in general relativity, we generalize the notion of a 4D spacetime M to a formal manifold M5=M×R, representing an admixture of geometry (the diffeomorphism invariance of M) and dynamics (the system evolution of Mτ with the monotonic advance of τR). Strategically breaking the formal 5D symmetry of a metric gαβ(x,τ) (α,β=0,1,2,3,5) posed on M5, we obtain ten unconstrained Einstein equations for the τ-evolution of the 4D metric γμν(x,τ) and five constraints that are to be satisfied by the initial conditions. The resulting theory differs from five-dimensional (5D) gravitation, much as SHP U(1) gauge theory differs from 5D electrodynamics. Full article
(This article belongs to the Special Issue New Advances of Cosmology and Astrophysics)
16 pages, 2799 KiB  
Article
Consortium Blockchain Smart Contracts for Musical Rights Governance in a Collective Management Organizations (CMOs) Use Case
by Nikolaos Kapsoulis, Alexandros Psychas, Georgios Palaiokrassas, Achilleas Marinakis, Antonios Litke, Theodora Varvarigou, Charalampos Bouchlis, Amaryllis Raouzaiou, Gonçal Calvo and Jordi Escudero Subirana
Future Internet 2020, 12(8), 134; https://doi.org/10.3390/fi12080134 - 11 Aug 2020
Cited by 13 | Viewed by 8896
Abstract
Private and permissioned blockchains are conceptualized and mostly assembled for fulfilling corporations’ demands and needs in the context of their own premises. This paper presents a complete and sophisticated end-to-end permissioned blockchain application for governance and management of musical rights endorsed by smart [...] Read more.
Private and permissioned blockchains are conceptualized and mostly assembled for fulfilling corporations’ demands and needs in the context of their own premises. This paper presents a complete and sophisticated end-to-end permissioned blockchain application for governance and management of musical rights endorsed by smart contract development. In a music industry use case, this disclosed solution monitors and regulates conflicting musical rights of diverse entities under a popular permissioned distributed ledger technology network. The proposed implementation couples various and distinct business domains across the music industry organizations and non-profit blockchain associations. Full article
(This article belongs to the Section Big Data and Augmented Intelligence)
Show Figures

Figure 1

9 pages, 246 KiB  
Article
The Relativistic Boltzmann Equation and Two Times
by L. P. Horwitz
Entropy 2020, 22(8), 804; https://doi.org/10.3390/e22080804 - 22 Jul 2020
Cited by 1 | Viewed by 2019
Abstract
We discuss a covariant relativistic Boltzmann equation which describes the evolution of a system of particles in spacetime evolving with a universal invariant parameter τ . The observed time t of Einstein and Maxwell, in the presence of interaction, is not necessarily a [...] Read more.
We discuss a covariant relativistic Boltzmann equation which describes the evolution of a system of particles in spacetime evolving with a universal invariant parameter τ . The observed time t of Einstein and Maxwell, in the presence of interaction, is not necessarily a monotonic function of τ . If t ( τ ) increases with τ , the worldline may be associated with a normal particle, but if it is decreasing in τ , it is observed in the laboratory as an antiparticle. This paper discusses the implications for entropy evolution in this relativistic framework. It is shown that if an ensemble of particles and antiparticles, converge in a region of pair annihilation, the entropy of the antiparticle beam may decreaase in time. Full article
(This article belongs to the Special Issue Time and Entropy)
Back to TopTop