Fermat’s principle and the effect of jerk on light motion near the Sun

In classical mechanics, in the case of gravitational and electromagnetic interactions, the force on a particle is usually proportional to its acceleration: The force acts locally on the particle. However, there are situations possible-if the particle moves through a suitable medium, for example, in which the force depends also on the first-time derivative of its acceleration, the jerk, and on its second-time derivative, the snap, and possibly also on higher-time derivatives. Such forces are called nonlocal, and this work investigates such nonlocal forces, mainly those depending on the jerk. In particular, we implement jerk and acceleration in geodesics by means of the nonlocal-in-time kinetic energy approach to spacetime physics. We describe a framework that can be used to estimate the quantum nonlocal time parameter by studying the deflection of light around the Sun. Comparing our results with long baseline interferometry (VLBI) observations, we concluded that the nonlocal time parameter [Formula: see text] s.

Composição histórica da teoria eletrofraca: da reformulação V-A à detecção dos bósons W+, W- e Z0

Este trabalho tem o objetivo de apresentar uma Composição Histórica a respeito de estudos que culminaram na elaboração da teoria de unificação das interações eletromagnéticas e fracas, a Teoria Eletrofraca. Entende-se que as contribuições teóricas e experimentais envolvidas nesse processo constituíram novos rumos para a Física de Partículas daquela época e elucidaram questões relevantes para o entendimento da estrutura da matéria. Neste artigo, serão apresentados estudos que partem da Teoria V-A, apresentam as primeiras hipóteses de bósons mediadores para a interação fraca, possíveis relações entre as interações fracas e eletromagnéticas, e as contribuições teóricas e experimentais que consolidaram a Teoria Eletrofraca. Este artigo foi elaborado com base em encaminhamentos metodológicos de pesquisas em História da Ciência e pressupostos da elaboração de uma Composição Histórica, considerando fontes primárias e seguindo os princípios de inteligibilidade, valores cognitivos e fidedignidade, que resultam em um material que reúne elementos históricos, epistemológicos, axiológicos e científicos para a inteligibilidade de um conteúdo científico com objetivos pedagógicos e de disseminação de conhecimentos.Historical composition of electroweak theory: from V-A reformulation to detection of W+, W- and Z0 bosonsAbstractThis paper aims to present a Historical Composition about studies that culminated in the elaboration of the theory of unification of weak and electromagnetic interactions, the Electroweak Theory. It is understood that the theoretical and experimental contributions involved in this process constitute new directions for Particle Physics of that time and clarified relevant issues for the understanding of the structure of matter. In this article we will present studies that depart from Theory V-A, present the first hypothesis of mediating bosons for the weak interaction, possible relations between weak and electromagnetic interactions, and the theoretical and experimental contributions that consolidated the Electro-Theory Theory. This article was elaborated based on methodological referrals of research in History of Science and assumptions of the elaboration of a Historical Composition, considering primary sources and following the principles of intelligibility, cognitive values and reliability, which result in a material that brings together historical, epistemological elements axiological and scientific for the intelligibility of a scientific content with pedagogical purpose and knowledge dissemination.Keywords: Electroweak theory; Historical composition; Unification; Historical experiments.

THE ONTOLOGICAL TRIANGLE OF THE RELATIONAL PARADIGM

The philosophical analysis of three main paradigms in the basis of physical knowledge is carried out. It is permissible to conclude that in the case of electromagnetic interaction between the emitter and the absorber: 1) the process of interaction of the photon with the medium in space and time can occur; 2) in the case when the photon “teleports” - there is only a relation outside of space and time. The following classification of fundamental concepts, with which the relational paradigm deals, is revealed. The ideal: space and time, field, information, a set of movements of quantum particles. The material: interactions, environment. Nothing more than countable: time, electromagnetic interactions. Uncountable: space, environment, interactions with the environment, a set of movements of quantum particles. Substantial: environment, interactions, information, a set of movements of quantum particles. Relational: space, time, field - as a means of description.

Model of electromagnetic interactions with spin-1/2 neutral particles

We address the bound-state dynamics of relativistic spin-1/2 neutral particles (in this paper, Dirac neutrinos) with anomalous magnetic dipole moment in the presence of an electromagnetic (EM) field described by a generalized Dirac–Pauli equation. This equation of motion is derived including appropriate couplings between Lorentz scalar and pseudoscalar fields with the EM field in the Lagrangian of the system. Specifically, we exactly solve the bound-state problem of neutrinos in the presence of a homogeneous magnetic field in cylindrical coordinates. We comment on the relevance of this approach to study Dirac neutrino self-interactions.

A Gauge Theory for the Weak and Electromagnetic Interactions

In this chapter we develop the Glashow–Weinberg–Salam theory of electromagnetic and weak interactions based on the gauge group SU(2) × U(1). We show that the apparent difference in strength between the two interactions is due to the Brout–Englert–Higgs phenomenon which results in heavy intermediate vector bosons. The model is presented first for the leptons, and then we argue that the extension to hadrons requires the introduction of a fourth quark. We show that the GIM mechanism guarantees the natural suppression of strangeness changing neutral currents. In the same spirit, the need to introduce a natural source of CP-violation leads to a six quark model with the Cabibbo–Kobayashi–Maskawa mass matrix.

The Electromagnetic Interactions

We briefly review the birth of renormalisation theory at the 1947 Shelter Island conference. We study the particular case of quantum electrodynamics in the example of an electron scattered by an external electromagnetic field. We give the general form of the amplitude in terms of form factors. At one loop the amplitude has both ultraviolet and infrared divergences. We show how to absorb the ultraviolet divergences by means of counterterms whose values are determined by the renormalisation conditions. We also show that at one loop order the electron anomalous magnetic moment is free of divergences, ultraviolet as well as infrared, and present its explicit calculation.

Coupling effects between elastic and electromagnetic fields from the perspective of conservation of energy

Coupling effects among different physical fields reflect the conversion of energies from one field into another substantially. For simple physical processes, their governing or constitutive equations all satisfy the law of conservation of energy (LCE). Then, an analysis is extended to the coupling effects. First, for the linear direct and converse piezoelectric and piezomagnetic effects, their constitutive equations guarantee that the total energy is conserved during the process of energy conversion between the elastic and electromagnetic fields. However, the energies are converted via the work terms, (βijkEi),kvj and (γijkHi),kvj, rather than via the energy terms, βijkEiejk and γijkHiejk. Second, for the generalized Villari effects, the electromagnetic energy can be treated as an extra contribution to the generalized elastic energy. Third, for electrostriction and magnetostriction, both effects are induced by the Maxwell stress. Moreover, their energies are purely electromagnetic and thus both have no converse effects. During these processes, the energies can be converted in three different ways, i.e., via the non-potential forces, via the cross-dependence of the energy terms, and directly via the electromagnetic interactions of ions and electrons. In the end, the general coupling processes which involve elastic, electromagnetic fields and diffusion are also analyzed. The advantages of using this energy formulation are that it facilitates discussion of the conversion of energies and provides better physical insights into the mechanisms of these coupling effects.