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The explanation of Einstein’s special theory of relativity in his original 1905 paper is examined. His analysis is confusing, as terms x, y, z, t, etc., have different meanings at various points, and he presents equations based on different and inconsistent assumptions. Adding subscripts clarifies these issues but exposes errors in his reasoning. To calculate his transformation equations, he selects a combination of equations which gives results matching the Lorentz transformation but he ignores other possible valid solutions. Also his calculations contain serious errors. Therefore, he fails to prove that his theory leads to the Lorentz equations as a unique solution. Einstein’s analysis includes “moving” clocks which show “stationary” time t, so the idea that a moving clock should run slower than a stationary clock is incompatible with his theory. Also, his calculation of time dilation contains serious errors. As a result, he fails to provide a theoretical justification for his famous “clocks paradox.” [ABSTRACT FROM AUTHOR]

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Reproducibility of results is a cornerstone of the scientific method. Scientific computing encounters two challenges when aiming for this goal. Firstly, reproducibility should not depend on details of the runtime environment, such as the compiler version or computing environment, so results are verifiable by third-parties. Secondly, different versions of software code executed in the same runtime environment should produce consistent numerical results for physical quantities. In this manuscript, we test the feasibility of reproducing scientific results obtained using the IllinoisGRMHD code that is part of an open-source community software for simulation in relativistic astrophysics, the Einstein Toolkit. We verify that numerical results of simulating a single isolated neutron star with IllinoisGRMHD can be reproduced, and compare them to results reported by the code authors in 2015. We use two different supercomputers: Expanse at SDSC, and Stampede2 at TACC. By compiling the source code archived along with the paper on both Expanse and Stampede2, we find that IllinoisGRMHD reproduces results published in its announcement paper up to errors comparable to round-off level changes in initial data parameters. We also verify that a current version of IllinoisGRMHD reproduces these results once we account for bug fixes which have occurred since the original publication. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In his groundbreaking 1905 paper on special relativity, Einstein distinguished between local and global time in inertial systems, introducing his famous definition of distant simultaneity to give physical content to the notion of global time. Over the following decade, Einstein attempted to generalize this analysis of relativistic time to include accelerated frames of reference, which, according to the principle of equivalence, should also account for time in the presence of gravity. Characteristically, Einstein's methodology during this period focused on simple, intuitively accessible physical situations, exhibiting a high degree of symmetry. However, in the final general theory of relativity, the a priori existence of such global symmetries cannot be assumed. Despite this, Einstein repeated some of his early reasoning patterns even in his 1916 review paper on general relativity and in later writings. Modern commentators have criticized these arguments as confused, invalid, and inconsistent. Here, we defend Einstein in the specific context of his use of global time and his derivations of the gravitational redshift formula. We argue that a detailed examination of Einstein's early work clarifies his later reasoning and demonstrates its consistency and validity. [ABSTRACT FROM AUTHOR]

The article reviews the web site Collected Papers of Albert Einstein, available at einsteinpapers.press.princeton.edu/, from Princeton University Press, the California Institute of Technology, and the Hebrew University of Jerusalem.

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In a 1936 manuscript submitted to the Physical Review, Albert Einstein and Nathan Rosen famously claimed that gravitational waves do not exist. It has generally been assumed that there was a conceptual error underlying this fallacious claim. It will be shown, through a detailed study of the extant referee report, that this claim was probably only the result of a calculational error, the accidental use of a pathological coordinate transformation. [ABSTRACT FROM AUTHOR]

During the 99 years of its history, the Journal of Comparative Physiology A has published many of the most influential papers in comparative physiology and related disciplines. To celebrate this achievement of the journal's authors, annual Editors' Choice Awards and Readers' Choice Awards are presented. The winners of the 2023 Editors' Choice Awards are 'Contact chemoreception in multi‑modal sensing of prey by Octopus' by Buresch et al. (J Comp Physiol A 208:435–442, 2022) in the Original Paper category; and 'Magnetic maps in animal navigation' by Lohmann et al. (J Comp Physiol A 208:41–67, 2022) in the Review/Review-History Article category. The winners of the 2023 Readers' Choice Awards are 'Coping with the cold and fighting the heat: thermal homeostasis of a superorganism, the honeybee colony' by Stabentheiner et al. (J Comp Physiol A 207:337–351; 2021) in the Original Paper category; and 'Einstein, von Frisch and the honeybee: a historical letter comes to light' by Dyer et al. (J Comp Physiol A 207:449–456, 2021) in the Review/Review-History category. [ABSTRACT FROM AUTHOR]

Arthur Stanley Eddington (1882–1944) was one of the leading astrophysicists of the first half of the 20th century. He is remembered today chiefly for his research into stellar structure and general relativity, both of which he began to explore in the mid-1910s. He was also a key participant in the famous eclipse expeditions of 1919 that tested Einstein's theory of gravity. Rather than consider these topics, in this paper I will instead examine Eddington's early astronomical career, that is, from 1906 to about 1915. In this period, he became a well-trained practical astronomer. Eddington also established himself as a brilliant theoretical astronomer, and in so doing helped to create the role of theoretical astrophysicist through his research into star streaming. He was also, unusually for astronomers of this period, an enthusiastic advocate of the use of "working hypotheses" as crucial tools in astronomical practice. The study of Eddington's early career therefore has much to tell us about the nature of astronomy in the years around 1910 and about Eddington. The paper underlines, for example, the continuing relevance of the "Greenwich-Cambridge Axis" for the power structure of British astronomy, and the importance of the so-called Sidereal Problem for astronomers at this time even though today it is largely forgotten. [ABSTRACT FROM AUTHOR]

Gravitational waves are being shown to derive directly from Newtonian dynamics for a continuous mass distribution, e.g. compressible fluids or equivalent. It is shown that the equations governing a continuous mass distribution, i.e. the inviscid Navier–Stokes equations for a general variable gravitational field g(t,x) , are equivalent to a form identical to the Maxwell equations from electromagnetism, subject to a specified condition. The consequence of this equivalence is the creation of gravity waves that propagate at a finite speed. The latter implies that Newtonian gravitation as presented in this paper is not 'spooky action at a distance' but rather is similar to electromagnetic waves propagating at finite speed, despite the apparent form appearing in the integrated field formula. In addition, this proves that, in analogy to the Maxwell equations, the Newtonian gravitation equations are Lorentz invariant for waves propagating at the speed of light. Since gravitational waves were so far derived only from Einstein's general relativity theory, it becomes appealing to check if there is a connection between the Newtonian waves presented in this paper and the general relativity type of waves at least in a certain limit of overlapping validity, i.e. as a flat-space approximation. The latter is left for follow-up research. [ABSTRACT FROM AUTHOR]

At first glance, thermodynamic properties of gravity with asymptotically AdS conditions and those with box boundary conditions, where the spatial section of the boundary is a sphere of finite radius, appear similar. Both exhibit a similar phase structure and Hawking-Page phase transition. However, when we introduce a U(1) gauge field to the system, discrepancies in thermodynamic properties between the two cases has been reported in [7] (JHEP 11 (2016) 041). In this paper, by accepting the assumption that all Euclidean saddles contribute to the partition function, I found that these discrepancies are resolved due to the contribution from the "bag of gold (BG)," which is the class of Euclidean geometries whose area of bolt is bigger than that of the boundary. As a result, the Hawking-Page phase structure is restored, with the unexpected properties that the upper bound of thermodynamic entropy is always larger than the boundary area divided by 4G when the chemical potential is non-zero, and that such high entropy states are realized at sufficiently high temperature. [ABSTRACT FROM AUTHOR]

This paper is the fourth in a series dedicated to the mathematically rigorous asymptotic analysis of gravitational radiation under astrophysically realistic set-ups. It provides an overview of the physical ideas involved in setting up the mathematical problem, the mathematical challenges that need to be overcome once the problem is posed, as well as the main new results we will obtain in upcoming work. From the physical perspective, this includes a discussion of how post-Newtonian theory provides a prediction on the gravitational radiation emitted by N infalling masses from the infinite past in the intermediate zone, i.e. up to some finite advanced time. From the mathematical perspective, we then take this prediction, together with the condition that there be no incoming radiation from I− , as a starting point to set up a scattering problem for the linearized Einstein vacuum equations around Schwarzschild and near spacelike infinity, and we outline how to solve this scattering problem and obtain the asymptotic properties of the scattering solution near i0 and I+. The full mathematical details will be presented in the sequel to this paper. This article is part of a discussion meeting issue 'At the interface of asymptotics, conformal methods and analysis in general relativity'. [ABSTRACT FROM AUTHOR]

Recently proposed duality relates the critical level limit of WZW models to a classical three-dimensional Einstein gravity on a sphere. In this paper, we propose a dimensional reduced version of this duality. The gravity side is reduced to a Jackiw-Teitelboim (JT) gravity on S2 with a non-standard boundary term, or a BF theory with SU(2) gauge symmetry. At least in low temperature limit, these two-dimensional gravity theories completely capture the original three-dimensional gravity effect. The CFT side is reduced to a certain complex Liouville quantum mechanics (LQM) with SU(2) gauge symmetry. Our proposal gives an interesting example of a holography without boundary. We also discuss a higher-spin generalization with SU(N) gauge symmetry. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of the present paper is to clarify, as far as it is possible, the overall picture of experimental results in the field of non-conventional phenomena in nuclear matter published in the scientific literature, accumulated in the past few decades and still missing a widely accepted interpretation. Completeness of the collection of the experiments is not among the aims of the effort; the focus is on adopting a more comprehensive and integral approach through the analysis of the different experimental layouts and different results, searching for common features and analogous factual outcomes in order to obtain a consistent reading of many experimental evidences that appear, so far, to lack a classification in a logic catalogue, which might be compared to a building rather than a collection of single stones. Particular attention is put on the issue of reproducibility of experiments and on the reasons why such a limitation is a frequent characteristic of many experimental activities reported in published papers. This approach is innovative as compared with those already available in the scientific literature. In a synoptical table, a comprehensive classification is given of the twenty experiments examined in terms of types of evidences that are ascertained by the experimenters in their published papers but are "unexpected" according to well-established physical theories. Examples of such unexpected evidences (named also non-conventional or weird) evidences are: excess heat generation, isotope production, reduction of radioactivity levels, and production of neutrons or alpha particles. These evidences are classified taking into account both the material where the evidence takes place (solutions, metals, rocks and artificial materials) and the stimulation techniques (supply of electric voltage, irradiation by photons, mechanical pressure) used to generate the evidences (which do not appear in the absence of such stimuli at an appropriate intensity). Also, in our paper, "identity cards" are provided for each experiment examined, including details that emerged during the experiment and were reported in each respective paper, that sometimes are not given adequate consideration either by the author of the experiment or in other review papers. The analysis of the details provides suggestions (also referred to as clues in this papers) used to formulate the content of the second part of each identity card, where inferences deduced from facts are outlined in view of presenting tentative interpretation at the microscopic level. This is done by concentrating attention on the clues repeated in different experiments in order to yield possible explanations of the "unexpected" evidences. The main outcome of such analysis is that, in all examined cases, a common "operation" can be identified: the stimulation techniques mentioned above can be interpreted as a sort of compression producing a ramp of energy densification (with reference to volumes in space or time coordinates). Here we use the term "compression" to indicate an operation activated by the experimenter; as such, it is objective. We consider energy densification an inference of possible consequences of the operation on the status of the system. Five types of densifications were identified. This reading in terms of energy densification is in accordance with the predictions of the Deformed Space Time theory, reported in the scientific literature, in the context of a generalization of the Einstein relativity theory, according to which the existence of energy thresholds is found to separate, for each interaction, the flat metric part from the deformed metric part and the appearance of new microscopic effects as a consequence of trespassing such thresholds. The phenomena occurring in the deformed part of the interaction metric are governed by the energy density in the space-time (volume and time interval). This energy density is computed from the threshold energies and is peculiar to the phenomenology under consideration. As a conclusion, it is suggested that the revealed qualified information, homogenized and elaborated on, might help in repeating, with proper adjustments and adequate additional instrumentation, some key experiments, in order to ensure systematic reproducibility, which is a prerequisite for interpretations and explanations to be sound and credible, as well in deriving from such an effort, indications for new experiments. It is uncomfortable that, after thirty years, there are still pending questions to which the most acknowledged physical theories are not capable of giving an answer. Even a definitive demonstration that all these experiments have decisive faults would be preferable than leaving the issue unaddressed. Major research agencies, for instance in the USA and in Europe, are moving in this direction. [ABSTRACT FROM AUTHOR]

This paper investigates GPT-4's role as a research partner, particularly its ability to scrutinize complex theories like Einstein's Special Relativity Theory (SRT). GPT-4's advanced capabilities prove invaluable in complex research scenarios where human expertise might be limited. Despite initial biases, an inclination to uphold Einstein's theory, and certain mathematical limitations, GPT-4 validated an inconsistency within the SRT equations, leading to a questioning of the theory's overall validity. GPT-4 contributed significantly to honing the analytical approach and expanding constraints. This paper explores the strengths and challenges associated with the use of GPT-4 in scientific research, with a strong emphasis on the need for vigilance concerning potential biases and limitations in large language models. The paper further introduces a categorization framework for AI collaborations, and specific guidelines for optimal interaction with advanced models like GPT-4. Future research endeavors should focus on augmenting these models' precision, trustworthiness, and impartiality, particularly within complex or contentious research domains. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the concepts of Riemannian warped-twisted product submersions and examine their fundamental properties, including total geodesicity, total umbilicity and minimality. Additionally, we investigate the Ricci tensor of Riemannian warped-twisted product submersions, specifically about the horizontal and vertical distributions. Finally, we obtain Einstein condition for base manifold if the horizontal and vertical distributions of the ambient manifold is Einstein. [ABSTRACT FROM AUTHOR]

The main object of the present paper is to discuss about the quarter symmetric metric connection on α-Sasakian Manifold with respect to Ricci Soliton. In this paper, firstly, we discuss the quarter symmetric metric connection on α-Sasakian manifold. Secondly, we elaborate the results of quarter symmetric metric connection on α-Sasakian manifold which admits Ricci Soliton and also flourish a non-trivial example of α-sasakian manifold and validate some of our results. Thirdly, we classify certain curvature properties of Ricci α-Sasakian manifold in regard to Quarter symmetric metric connection. Finally, we show Ricci Soliton on submanifold of α-Sasakian manifold in term of Levi-Civita and quarter symmetric metric connection. [ABSTRACT FROM AUTHOR]

Photonspheres, curved hypersurfaces on which massless particles can perform closed geodesic motions around highly compact objects, are an integral part of generic black-hole spacetimes. In the present compact paper we prove, using analytical techniques, that the innermost light rings of spherically symmetric hairy black-hole spacetimes whose external matter fields are characterized by a traceless energy-momentum tensor cannot be located arbitrarily close to the central black hole. In particular, we reveal the physically interesting fact that the non-linearly coupled Einstein-matter field equations set the lower bound r γ ≥ 6 5 r H on the radii of traceless black-hole photonspheres, where rH is the radius of the outermost black-hole horizon. [ABSTRACT FROM AUTHOR]

This research paper explores the properties of quasi-Einstein manifolds with a unit concircular generator vector field within doubly warped product structures. The paper begins by investigating the characteristics of quasi-Einstein manifolds that possess a unit concircular generator vector field. Subsequently, it analyzes the behavior of the Hessian, Riemann, and Ricci vector fields in the context of a doubly warped product. Moreover, the impact of the quasi-Einstein condition on both the doubly warped product and its factor manifolds is studied. Finally, conditions are derived to determine whether a doubly warped product satisfying the quasi-Einstein condition can be classified as a warped or a direct product. By presenting these findings, this study contributes to the comprehension of quasi-Einstein manifolds and their interactions within doubly warped product structures. [ABSTRACT FROM AUTHOR]

In this paper, we aim to characterize the sequential warped product κ -almost gradient conformal Ricci–Bourguignon soliton. We derive applications of some vector fields like conformal vector field, torse-forming vector field, torqued vector field on κ -almost conformal Ricci–Bourguignon soliton. The inheritance properties of the Einstein-like sequential warped product κ -almost gradient conformal Ricci–Bourguignon solitons of class types ℙ , , are investigated in this paper. Later we show that if M ̄ = (M 1 × f I M 2 ) × f ̄ I M 3 is a sequential warped product of a complete connected (n − 2) -dimensional Riemannian manifold M 1 and one-dimensional Riemannian manifolds I M 2 and I M 3 admitting κ -almost conformal Ricci–Bourguignon soliton, then (M 1 , g 1) becomes a (n − 2) -dimensional sphere of radius ρ = n − 2 r 1 + (μ − 1 2 (p + 2 n) + ρ R) (4 − n) . We have discovered that for a κ -almost gradient conformal Ricci–Bourguignon soliton sequential warped product, the warping functions are constants under certain conditions. [ABSTRACT FROM AUTHOR]

In this study, we characterize LP-Kenmotsu manifolds admitting *-Ricci-Yamabe solitons (*-RYSs) and gradient *-Ricci-Yamabe solitons (gradient *-RYSs). It is shown that an LP-Kenmotsu manifold of dimension n admitting a *-Ricci-Yamabe soliton obeys Poisson's equation. We also determine the necessary and sufficient conditions under which the Laplace equation is satisfied by LP-Kenmotsu manifolds. Finally, by using a non-trivial example of an LP-Kenmotsu manifold, we verify some results of our paper. [ABSTRACT FROM AUTHOR]

In the present paper, we investigate perfect fluid spacetimes and perfect fluid generalized Roberston-Walker spacetimes that contain a torse-forming vector field satisfying almost hyperbolic Ricci solitons. We show that the perfect fluid spacetimes that contain a torse-forming vector field satisfy an almost hyperbolic Ricci soliton, and we prove that a perfect fluid generalized Roberston-Walker spacetime satisfying an almost hyperbolic Ricci soliton (g, ζ, ..., µ) is an Einstein manifold. Also, we study an almost hyperbolic Ricci soliton (g, V, ..., µ) on these spacetimes when V is a conformal vector field, a torse-forming vector field, or a Ricci bi-conformal vector field. [ABSTRACT FROM AUTHOR]

Is it possible for today's man to return to the historical past several centuries or millennia and find himself among his ancestors as shown in various science fiction films such as the cult British series "Outlander" when the main heroine enters the hollow of the tree and returns in the middle ages. Is it possible to travel into the future several centuries or millennia into the future as shown by Herbert George Wells in the science fiction novel Time machine or the French film "Les Visiteurs" when the heroes of the Middle Ages travel to the future. Are there parallel worlds or multiverses in which one day future generations will travel only with advanced technologies at the speed of light like in the cult TV series Wars or Dr.No? For now, these impossible feats are possible only on movies, but scientists like Albert Einstein, Nikola Tesla, and especially Everett Hughes, Stephen Hawking, theoretically explained the probability of such hypotheses. The concepts of time travel and parallel worlds are phenomena that are mutually related and interdependent both in literature and cinema, and in other scientific cultural-artistic or entertainment works. They complement and enhance each other because the phenomenon of time travel cannot be effected if there is no other world, even assuming that it is simply a return to the past or travel to the future. In this review, we will only focus on the phenomenon of time travel. This paper is part of the research dedicated to the project Time Travel and Parallel Worlds in Cinema integrated in my doctoral thesis with the same title. [ABSTRACT FROM AUTHOR]

In a recent series of papers new exact analytical interior spacetimes sourced by stationary rigidly rotating cylinders of fluids have been displayed. A fluid with an axially directed pressure has been first considered, then a perfect fluid, followed by a fluid with an azimuthally directed pressure, and, finally, by a fluid where the pressure is radially oriented. The perfect fluid configuration has subsequently been extended to the case of differential rotation. In the present paper, three different cases of anisotropic pressure analogous to those studied for rigidly rotating motion are considered in turn for differentially rotating fluids. General methods for generating mathematical solutions to the field equations and physically well-behaved examples are displayed for the axial and azimuthal pressure cases. As regards radial pressure fluids, four classes of solutions naturally emerge from the corresponding Einstein's equations, among which one class, after being fully integrated, exhibits physically well-behaved solutions. [ABSTRACT FROM AUTHOR]

In this paper, we study quintessence compact stars in the paradigm of pure Lovelock gravity. We derive the field equations using a spherically symmetric space–time. Specifically, we discuss the equivalence of Einstein's Lovelock gravity in four-dimensional space–time, Gauss–Bonnet term equivalent Lovelock gravity in seven-dimensional space–time and sixteen-dimensional Lovelock gravity by exploring the impact of the quintessence field parameter on features of compact stars in anisotropic matter fields. For matter inside the star, we use Tolman–Kuchowiz space–time. We discuss the density of the compact star and the density related to the quintessence matter field. We also explore the pressure profiles, anisotropy, speeds of sound for stability, EoS state parameters, mass-to-radius profile, compactification, gravitational and gradients for different values of N, which change the dimensions ( d = 3 N + 1 ) of pure Lovelock gravity. [ABSTRACT FROM AUTHOR]

This paper explains how the so-called Einstein locality is to be understood in the Schrödinger picture of quantum mechanics. This notion is fully compatible with the Bell non-locality exhibited by entangled states. Contrary to the belief that quantum mechanics is incomplete, it is, As a matter of fact, its overcompleteness, as exemplified by the different pictures of quantum physics, that points to the same underlying reality. [ABSTRACT FROM AUTHOR]

The modern textbook analysis of the thermal state of photons inside a three-dimensional reflective cavity is based on the three quantum numbers that characterize photon's energy eigenvalues coming out when the boundary conditions are imposed. The crucial passage from the quantum numbers to the continuous frequency is operated by introducing a three-dimensional continuous version of the three discrete quantum numbers, which leads to the energy spectral density and to the entropy spectral density. This standard analysis obscures the role of the multiplicity of energy eigenvalues associated to the same eigenfrequency. In this paper we review the past derivations of Bose's entropy spectral density and present a new analysis of energy spectral density and entropy spectral density based on the multiplicity of energy eigenvalues. Our analysis explicitly defines the eigenfrequency distribution of energy and entropy and uses it as a starting point for the passage from the discrete eigenfrequencies to the continuous frequency. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the present paper we study Ricci pseudo-symmetry, Z-Ricci pseudo-symmetry and concircularly pseudo-symmetry conditions on a mixed generalized quasi-Einstein spacetime MG(QE)4. Also, it is proven that if d ≠ Λ, then MG(QE)4 spacetime does not admit heat flux, where d and Λ are the function and the cosmological constant, respectively. In the end of this paper we construct a non-trivial example of MG(QE)4 to prove its existence. [ABSTRACT FROM AUTHOR]

The objective of this paper is to investigate the Lorentzian Kähler space-time manifold that is Bochner flat. We have demonstrated that a Lorentzian Kähler space-time manifold with Bochner flatness is also an Einstein manifold. Furthermore, we have established that the energy-momentum tensor is covariantly constant when the manifold satisfies the Einstein field equation with a cosmological constant. Additionally, we have determined that the energy-momentum tensor of a perfect fluid Lorentzian Kähler space-time manifold exhibits hybrid characteristics. In the final section, we analyse the behaviour of a dust fluid Lorentzian Kähler space-time manifold where the Bochner curvature vanishes. [ABSTRACT FROM AUTHOR]

In Einstein's General Relativity (GR), the gravitational interactions are described by the spacetime curvature. Recently, other alternative geometric formulations and representations of GR have emerged in which the gravitational interactions are described by the so-called torsion or non-metricity. Here, we consider the recently proposed modified symmetric teleparallel theory of gravity or f (Q) gravity, where Q represents the non-metricity scalar. In this paper, motivated by several papers in the literature, we assume the power-law form of the function f (Q) as f (Q) = α Q n + 1 + β , (where α , β , and n are free model parameters) that contains two models: Linear (n = 0) and nonlinear (n ≠ 0). Further, to add constraints to the field equations we assume the deceleration parameter form as a divergence-free parametrization. Then, we discuss the behavior of various cosmographic and cosmological parameters such as the jerk, snap, lerk, O m diagnostic, cosmic energy density, isotropic pressure, and equation of state (EoS) parameter with a check of the violation of the strong energy condition (SEC) to obtain the acceleration phase of the Universe. Hence, we conclude that our cosmological f (Q) models behave like quintessence dark energy (DE). [ABSTRACT FROM AUTHOR]

Albert Einstein proposed a unification of mechanics and electrodynamics by his special theory of relativity, which describes point-like particles moving through empty space. We show in this paper that mechanics and electrodynamics can be unified in Euclidean space if we relax the idea of point-like particles by describing fermions and bosons as spatially extended wave objects. Based on the process theory of gases presented in Paper II [Kalies et al., AIP Adv. 13(5), 055317 (2023)] of this series, we consider a confined photon gas and show that the momentum work of photons leads to an analogous description of matter and light and to the insight that electromagnetic energy is momentum energy. We present the unified energy equations, which do justice to the wave nature of matter, and it is the momentum work that links physical theories. Without momentum energy, which is larger in real terms than the kinetic energy of mechanics, the theoretical edifice of modern physics, at the fundamental level, is incomplete. [ABSTRACT FROM AUTHOR]

The violation of Lorentz invariance (LI) in gravitational theories, which allows superluminal propagations, dramatically alters the causal structure of the spacetime and modifies the notion of black holes (BHs). Instead of metric horizons, now universal horizons (UHs) define the boundaries of BHs, within which a particle cannot escape to spatial infinities even with an infinitely large speed. Then, a natural question is how the quasi-normal modes (QNMs) of a BH are modified, if one considers the UH as its causal boundary. In this paper, we study in detail this problem in Einstein–Aether theory, a vector-tensor theory that violates LI but yet is self-consistent and satisfies all observations to date. Technically, this poses several challenges, including singularities of the perturbation equations across metric horizons and proper identifications of ingoing modes at UHs. After overcoming these difficulties, we show that the QNMs of the Schwarzschild BH, also a solution of Einstein–Aether theory, consist of two parts, the metric and aether parts. The QNMs of the metric perturbations are quite similar to those obtained in general relativity and are consistent with current observations of gravitational waves. But the ones from aether perturbations are different, and our numerical studies indicate that they are even not stable. The latter is consistent with our previous studies, which showed that the stealth Schwarzschild BH suffers a Laplacian instability along the angular direction. The method and techniques developed in this paper can be applied to the studies of QNMs in other theories of gravity with broken LI. [ABSTRACT FROM AUTHOR]

It was Albert Einstein, a world-renowned physicist who first said that laws alone cannot secure freedom of expression; in order that every man presents his views without penalty there must be a spirit of tolerance in the entire population. By this, he posited that the safeguards of law alone could not preserve, protect or assure the continued existence and respect for human rights, particularly, freedom of expression. On the contrary, recognition, respect and protection of the freedom of expression can only be achieved by a concerted effort of the citizenry to tolerate one another's differences despite the supremacy of their human rights. This is important even as the world continues to witness an exponential increase in the modes and mediums of expression both in person, and virtually. Even more so, as democracies continue to be threatened by State clamp down on free speech among the citizenry. This paper delves into Einstein's postulation by examining the concepts of human rights, freedom of expression, and tolerance; and underlining the need for the latter in the propagation and preservation of the former. The paper also examines the lawful and unlawful limits to the right to freedom of expression, and practical ways of achieving tolerance amongst the citizenry, in furtherance of the fundamental right to freedom of expression. The paper goes on to suggest different approaches to engendering tolerance in the citizenry and the expected outcome. The paper concludes by aligning with the postulation of Sir Albert that indeed, tolerance is a key ingredient for preserving and enforcing freedom of expression in Nigeria, and the world over. [ABSTRACT FROM AUTHOR]

Superionic (SI) water ices—high-temperature, high-pressure phases of water in which oxygen ions occupy a regular crystal lattice whereas the protons flow in a liquid-like manner—have attracted a growing amount of attention over the past few years, in particular due to their possible role in the magnetic anomalies of the ice giants Neptune and Uranus. In this paper, we consider the calculation of the free energies of such phases, exploring hybrid reference systems consisting of a combination of an Einstein solid for the oxygen ions occupying a crystal lattice and a Uhlenbeck-Ford potential for the protonic fluid that avoids irregularities associated with possible particle overlaps. Applying this approach to a recent neural-network potential-energy landscape for SI water ice, we compute Gibbs free energies as a function of temperature for the SI fcc and liquid phases to determine the melting temperature Tm at 340 GPa. The results are consistent with previous estimates and indicate that the entropy difference between both phases is comparatively small, in particular due to the large amplitude of vibration of the oxygen ions in the fcc phase at the melting temperature. [ABSTRACT FROM AUTHOR]

The strategic goal of all companies is sustainable and profitable growth which includes improving the firm's competitive position, achieving efficient utilization of resources, and maximizing the return on investments in product development. Unfortunately, many companies take a rather passive view on how strategic goals can be achieved and believe that doing business the same old way will continue to be successful in the future. As stated by Albert Einstein, "Insanity: doing the same thing over and over again and expecting different results." Companies must understand how project management best practices can elevate their levels of business success and recognize the need for continuous improvements supported by an investment in the discovery of best practices. Most organizations today realize they are managing their business by projects. Project management is no longer restricted to a few functional domains but is now utilized throughout the organization. Today, project management is viewed as a strategic competency needed for corporate growth rather than a career path. Project management is becoming the vehicle needed to capture, evaluate, and implement the best practices needed for continuous improvements in the firm's performance. Unfortunately, many companies have a relatively poor understanding of the steps needed to effectively capture and employ best practices. The intent of this paper is to provide a roadmap for how project management can maximize continuous improvement efforts utilizing best practices and strengthen the value and relevance that project management brings to the organization's future. [ABSTRACT FROM AUTHOR]

We present JWST and Atacama Large Millimeter/submillimeter Array (ALMA) imaging for the lensing system SPT0418−47, which includes a strongly lensed, dusty, star-forming galaxy at redshift z = 4.225 and an associated multiply imaged companion. The JWST NIRCam and MIRI imaging observations presented in this paper were acquired as part of the Early Release Science program Targeting Extremely Magnified Panchromatic Lensed Arcs and Their Extended Star formation (TEMPLATES). This data set provides robust mutiwavelength detections of stellar light in both the main (SPT0418A) and companion (SPT0418B) galaxies, while the ALMA detection of [C ii ] emission confirms that SPT0418B lies at the same redshift as SPT0418A. We infer that the projected physical separation of the two galaxies is 4.42 ± 0.05 kpc. We derive total magnifications of μ = 29 ± 1 and μ = 4.1 ± 0.7 for SPT0418A and SPT0418B, respectively. We use both prospector and cigale to derive stellar masses. We find that SPT0418A has a stellar mass of M * = 3.4 − 0.6 + 1.1 × 10 10 M ⊙ from prospector or M * = 1.5 ± 0.3 × 1010 M ⊙ from cigale. The stellar mass ratio of SPT0418A and SPT0418B is roughly between 4 and 7 ( 4.2 − 1.6 + 1.9 for prospector and 7.5 ± 3.7 for cigale). We see evidence of extended structure associated with SPT0418A that is suggestive of a tidal feature. These features, along with the close projected proximity, imply that the system is interacting. Interestingly, the star formation rates and stellar masses of both galaxies are consistent with the main sequence of star-forming galaxies at this epoch, indicating that this ongoing interaction has not noticeably elevated the star formation levels. [ABSTRACT FROM AUTHOR]

The neuroscience of creativity is built on a tacit and near universal assumption that is false. Paradoxically, this is not contentious; once made explicit, the assumption is readily conceded as false. Psychology regards creativity as made up of many complex, multifaceted, and varied cognitive and emotional processes deployed across many different domains. But we instead think of, and treat, creativity as if it were a single, separate, cohesive, and discrete thing--as in, Einstein had it. In a straightforward extension of this fallacy, cognitive neuroscientists have looked for uniquely creative cognition that (1) is distinct from all other kinds of cognition and (2) has a proprietary neural substrate. In other words, a standalone and monolithic creativity faculty in the brain that manages only creativity and all creativity. First, this paper brings into sharp focus the nature and ubiquity of this fallacy. It then outlines the alternative theoretical position that is (1) based on fundamental neural principles and (2) predicated on taking seriously the concept of creativity as complex and diverse. Like morality or secretiveness, it holds that creativity does not exist as its own, specialized entity in the brain. Instead, its neurocognitive mechanisms are distributed, embedded, and varied; that is, creativity is everywhere and multiply realizable. [ABSTRACT FROM AUTHOR]

In my paper I consider the movement of objects in „space", taking into account the idea of preserving and accumulation of change with time. I compare this view with Newton, Leibniz and Einstein's ideas of movement, space and time. To illustrate this, I represent the movement of two objects along a straight line, as well as some dependences connected to it. I also pose questions as "Why and how the things exist?" in relation to characteristics like discernibility, equality, and change. I also address faith as an integral part of science. [ABSTRACT FROM AUTHOR]

In this paper, we study the Minkowski-type inequality for asymptotically flat static manifolds (M^{n},g) with boundary and with dimension n<8 that was established by McCormick [Proc. Amer. Math. Soc. 146 (2018), pp. 4039–4046]. First, we show that any asymptotically flat static (M^{n},g) which achieves the equality and has CMC or equipotential boundary is isometric to a rotationally symmetric region of the Schwarzschild manifold. Then, we apply conformal techniques to derive a new Minkowski-type inequality for the level sets of bounded static potentials. Taken together, these provide a robust approach to detecting rotational symmetry of asymptotically flat static systems. As an application, we prove global uniqueness of static metric extensions for the Bartnik data induced by both Schwarzschild coordinate spheres and Euclidean coordinate spheres in dimension n < 8 under the natural condition of Schwarzschild stability. This generalizes an earlier result of Miao [Classical Quantum Gravity 22 (2005), pp. L53–L59]. We also establish uniqueness for equipotential photon surfaces with small Einstein-Hilbert energy. This is interesting to compare with other recent uniqueness results for static photon surfaces and black holes, e.g. see V. Agostiniani and L. Mazzieri [Comm. Math. Phys. 355 (2017), pp. 261–301], C. Cederbaum and G. J. Galloway [J. Math. Phys. 62 (2021), p. 22], and S. Raulot [Classical Quantum Gravity 38 (2021), p. 22]. [ABSTRACT FROM AUTHOR]

Einsteinian cubic gravity (ECG) is the most general theory up to cubic order in curvature, which has the same graviton spectrum as the Einstein theory. In this paper, we investigate the geodesic motions of timelike particles around the four dimensional asymptotically flat black holes in ECG, and discuss their potential applications when connecting them with recent observational results. We first explore the effects of the cubic couplings on the marginally bound orbits (MBO), innermost stable circular orbits (ISCO) and on the periodic orbits around the Einsteinian cubic black hole. We find that comparing to Schwarzschild black hole in general relativity, the cubic coupling enhances the energy as well as the angular momentum for all the bound orbits of the particles. Then, we derive the relativistic periastron precessions of the particles and give a preliminary bound on the cubic coupling employing the observational result of the S2 star's pericenter precession in SgrA*. Finally, after calculating the periodic orbits' configurations, we preliminarily evaluate the gravitational waveform radiated from several periodic orbits in one complete period of a test object which orbits a supermassive Einsteinian cubic black hole. Our studies could be helpful for us to better understand the gravitational structure of the theory with high curvatures. [ABSTRACT FROM AUTHOR]

Considering that Einstein's relation between the diffusion coefficient and the drift mobility of free randomly moving charge carriers in homogeneous materials including metals is always valid, it is shown that the effective electric force acting on free electrons in metal depends on the ratio between the kinetic free electron energy at the Fermi surface to the classical particle energy 3 kT/2. The electrical resistivity of elemental metals dependence on very low temperatures has the quadratic term, which has been explained by electron–electron scattering. In this paper, it is shown that the quadratic term of the electrical resistivity at low temperatures is caused by scattering of the free randomly moving electrons by electronic defects due to linear effective free electron scattering cross-section dependence on temperature, but not by electron–electron scattering. [ABSTRACT FROM AUTHOR]

In this paper, we study the gravitational waves of holographic QCD phase transition with hyperscaling violation. We consider an Einstein–Maxwell Dilaton background and discuss the confinement–deconfinement phase transition between thermally charged AdS and AdS black holes. We find that hyperscaling violation reduces the phase transition temperature. In a further study, we discuss the effect of hyperscaling violation on the GW spectrum. We found that the hyperscaling violation exponent suppresses the peak frequency of the total GW spectrum. Moreover, the results of the GW spectrum may be detected by IPTA, SKA, BBO, and NANOGrav. We also find that the hyperscaling violation exponent suppresses the peak frequency of the bubble-collision spectrum h 2 Ω e n v . Hyperscaling violation enhances the energy densities of the sound wave spectrum h 2 Ω s w and the MHD turbulence spectrum h 2 Ω t u r b . The total GW spectrum is dominated by the contribution of the bubble collision in runaway bubbles case. [ABSTRACT FROM AUTHOR]