Some classical solutions of the sourceless SO(4,1) gauge field equations

Some new classical solutions of the sourceless SO(4,1) gauge field equations are found by identifying the internal symmetry indices with the space-time indices as in the cases of the instanton or the meron solutions. This identification of the internal and the space-time indices takes the simplest form when the gauge field equation is expressed in (4,1) de Sitter space, which is conformal to the Minkowski space having the de Sitter group SO(4,1) as a group of motions. The form of the solutions is close to the de Sitter ‘plane wave’ solutions found recently, i.e. the solutions of the Klein-Gordon, Dirac and Maxwell-Proca equations in de Sitter space. The group theoretical structure of the new solutions is discussed and their relations to the Iwasawa decomposition of the non-compact semisimple group SO(4,1) are pointed out.     

Infinite sets of conservation laws for linear and nonlinear field equations

The relation between an infinite set of conservation laws of a linear field equation and the enveloping algebra of the space-time symmetry group is established. It is shown that each symmetric element of the enveloping algebra of the space-time symmetry group of a linear field equation generates a one-parameter group of symmetries of the field equation. The cases of the Maxwell and Dirac equations are studied in detail. Then it is shown that (at least in the sense of a power series in the coupling constant) the conservation laws of the linear case can be deformed to conservation laws of a nonlinear field equation which is obtained from the linear one by adding a nonlinear term invariant under the group of space-time symmetries. As an example, our method is applied to the Korteweg-de Vries equation and to the massless Thirring model.     

Rindler effect for a nonuniformly accelerating observer

Both the Klein-Gordon equation and the Dirac equation are dealt with in the generalized Rindler space-time of a nonuniformly accelerating observer. Making use of a new method and introducing a tortoise-type coordinate transformation, it is proved that there exist an event horizon and thermal radiation depending on time in the space-time. The Hawking-Unruh temperature is proportional to the variable acceleration.     

Fermi field and Dirac oscillator in a Som–Raychaudhuri space-time

We investigate the relativistic dynamics of a Dirac field in the Som–Raychaudhuri space-time, which is described by a Gödel-type metric and a stationary cylindrical symmetric solution of Einstein field equations for a charged dust distribution in rigid rotation. In order to analyze the effect of various physical parameters of this space-time, we solve the Dirac equation in the Som–Raychaudhuri space-time and obtain the energy levels and eigenfunctions of the Dirac operator by using the Nikiforov–Uvarov method. We also examine the behaviour of the Dirac oscillator in the Som–Raychaudhuri space-time, in particular, the effect of its frequency and the vorticity parameter.     

Internal symmetry of hadrons: Finsler geometrical origin

The microlocal space of hadronic matter extension has recently been characterized as a Finsler space. This consideration of hadrons extended as composites of constituents can give rise to a dynamical theory of hadrons. The macrospaces, the space-time of common experience (the Minkowski flat space-time) and the Robertson-Walker background space-time of the universe, are found to appear as the “averaged” space-times of the Finsler space that describes the anisotropic nature of the microdomain of hadrons. From the assumed property of the fields of the constituents in the microspace it is possible to find the field (or wave) equations of the particles (or constituents) through the quantization of space-time at small distances (to an order of or less than a fundamental length). If the field (or wave) function is separable in the functions of the coordinates of the underlying manifold and the directional arguments of the Finsler space, then the former part of the field function is found to satisfy the Dirac equation in the Minkowski space-time or in the Robertson-Walker space-time according to the nature of the underlying manifold. In the course of finding a solution for the other part of the field function a relation between the mass of the particle and a parameter in the metric of the space-time has been obtained as a byproduct. This mass relation has cosmological implications and is relevant in the very early stage of the evolution of the universe. In fact, it has been shown elsewhere that the universe might have originated from a nonsingular origin with entropy and matter creations that can account for the observed photon-to-baryon ratio and total particle number of the present universe. The equations in the directional arguments for the constituents in the hadron configuration are found here and give rise to an additional quantum number in the form of an “internal” helicity that can generate the internal symmetry of hadron if one incorporates the arguments of Budini in generating the internal isospin algebra from the conformal reflection group. This consideration can also account for the meson-baryon mass differences.     

Kernel of the classicalZitterbewegung

Barut's classicalzitterbewegung model includes the internal dynamical variables and the quantization of this system gives a general transition amplitude between the different space-time points and internal coordinates and momentum. It includes the transition amplitude between the half integer and integer spin eigenvalues. Spin eigenfunctions lead to all sets of relativistic wave equations, as well as the Dirac equation.     

Kerr-Newman-De Sitter时空中的Dirac方程的退耦和分离变量

本文给出了Kerr-Newman-De Sitter时空中的Dirac方程的退耦和分离变量,并在Kerr-Newman-De Sitter时空的视界附近通过适当的变换找到了静止质量不为零的Dirac方程的有物理意义的解,导出了Hawking热谱公式,从而解决了Dirac粒子在Kerr-Newman-De Sitter黑洞背景下的Hawking蒸发问题。 关键词：     

Hawking thermal radiation of the dirac particle in spherically symmetric nonstatic space-time

The dynamical properties of Dirac spinor particles in a spherically symmetric nonstatic space-time are studied. The explicit representative of the four-component wave function of Dirac particles is obtained. The Dirac equation can be reduced to the standard form of the wave equation near the event horizon by the proper coordinate transformation. The event horizon location and Hawking radiation temperature are obtained.     

Second Quantization of the Dirac Field: Normal Modes in the Robertson–Walker Space-Time

The quantization of the Dirac field in thecontext of the Robertson–Walker spacetime isreconsidered in some of its constitutive elements. Theparticular solutions of the Dirac equation previouslydetermined are used to construct the normal mode solutionsin the case of flat, closed, and open space-time. Theprocedure is based on a general standard definition ofinner product between solutions of the Dirac equation that is applied by making use of anintegral property of the separated time equation. Theopen-space case requires the recurrence relations offunctions associated to solutions of the Diracequation.     

Symmetry and invariance

The concept of invariance relates to both the intrinsic symmetries of physical systems and the symmetry of the set of equivalent reference frames used to observe them. Standard algebraic expressions for electrostatic potentials and crystal-field effective operators display both types of invariance. The concept of a reference frame is generalized to that of an ‘observing system’, which can, for example, be the basis states of a quantum system. This idea is related to Racah’s mathematical machinery for evaluating the matrix elements of many-electron 4f open-shell states in lanthanide ions. It is argued, on the basis of computational flexibility and ease of interpretation, that all equations that represent physical processes be expressible in terms of invariants of the set of observing systems. This ‘Principle of Invariance’ is then applied to special relativity, leading to a simple geometrical interpretation of Maxwell’s electromagnetic field equations. The close relationship between Dirac’s relativistic wave equation and Maxwell’s equations is then exposed. This leads to the concept of an inner structure of space-time and the reinterpretation of particle spin. Finally, it is shown that the use of invariants in relativity theory identifies a set of observing systems with a higher symmetry than that of Minkowski space-time.     

Space-time structure of weak and electromagnetic interactions

The generator of electromagnetic gauge transformations in the Dirac equation has a unique geometric interpretation and a unique extension to the generators of the gauge group SU(2) × U(1) for the Weinberg-Salam theory of weak and electromagnetic interactions. It follows that internal symmetries of the weak interactions can be interpreted as space-time symmetries of spinor fields in the Dirac algebra. The possibilities for interpreting strong interaction symmetries in a similar way are highly restricted.     

Dirac equation in (1+1)-dimensional curved space-time

The Dirac equation in (1+1)-dimensional curved space-time is solved explicitly for the spatially flat Robertson-Walker space-time and the cigar metric considered by Witten.     

Some Problems of the Existence of Symmetry Spinor Operators for the Dirac Equation

Conditions necessary for the existence of a class of fields that can be used to construct the spinor symmetry operators for the Dirac equation in Riemannian space are specified in the present paper. The metrics of spaces with four-dimensional groups of motions in which these fields exist are indicated. A class of spaces is identified in which the Dirac equation admits no separation of variables within the framework of the definition adopted, but the algebra of symmetry of the Dirac equation satisfies the conditions of theorems of the noncommutative intergrability.     

Evidence for special relativity with de Sitter space-time symmetry

I show the formulation of de Sitter Special Relativity (dS-SR) based on Dirac-Lu-Zou-Guo's discussions, dS-SR quantum mechanics is formulated, and the dS-SR Dirac equation for hydrogen is suggested. The equation in the earth-QSO framework reference is solved by means of the adiabatic approach. It's found that the fine-structure "constant" α in dS-SR varies with time. By means of the t-z relation of the ACDM model, α's time-dependency becomes redshift z-dependent. The dS-SR's predictions of △α/α agree with data of spectra of 143 quasar absorption systems, the dS-space-time symmetry is SO(3,2) (i.e., anti-dS group) and the universal parameter R (de Sitter ratio) in dS-SR is estimated to be R ≈ 2.73 x 10<'12> ly. The effects of dS-SR become visible at the cosmic space-time scale (i.e., the distance≥ 10<'9> ly). At that scale, dS-SR is more reliable than Einstein SR. The α-variation with time is evidence of SR with de Sitter symmetry.     

The Einstein-Dirac Equation in Robertson-Walker Space-Time Does Not Admit Standard Solutions

The Einstein-Dirac equation is considered in the Robertson-Walker space-time. Solutions of the equation are looked for in the class of standard solutions of the Dirac equation. It is shown that the Einstein-Dirac equation does not have standard solutions for both massive and massless Dirac field. Also superpositions of massive standard solutions are not solutions of the Einstein-Dirac equation. The result, that is briefly commented, is coherent and complementary to other existing results.     

Dirac粒子的Hawking蒸发

在Kerr背景时空中求解Dirac方程是一个长期没有解决的问题。1976年Chandrasekhar成功地找到了Kerr背景时空中静止质量不为零的Dirac方程的退耦和分离变量的量子方程。本文在此基础上,在近似极端Kerr黑洞的事件视界附近找到了静止质量不为零的Dirac方程的解,并成功地导出了Hawking热谱公式,从而解决了Dirac粒子在Kerr黑洞的Hawking蒸发问题。 关键词：     

Die quantenmechanische Interpretation der allgemeinkovarianten Dirac-Gleichung und die 8-parametrische Gruppe der Spinor-Transformationen

The Quantum Mechanical Interpretation of the General-covariant Dirac Equation and the 8-Parametrical Group of the Spinor-Transformation With respect to nonunimodular spinor-transformations covariant Dirac equation is investigated. It is shown, that even in the flat space-time in cartesian coordinates this equation can only be interpreted as a quantum mechanical equation of motion in the position representation if the basis spanning the Hilbert space is given by a nonorthonormal set of vectors.     

Maximal symmetry and mass generation of Dirac fermions and gravitational gauge field theory in six-dimensional spacetime

The relativistic Dirac equation in four-dimensional spacetime reveals a coherent relation between the dimensions of spacetime and the degrees of freedom of fermionic spinors. A massless Dirac fermion generates new symmetries corresponding to chirality spin and charge spin as well as conformal scaling transformations. With the introduction of intrinsic W-parity, a massless Dirac fermion can be treated as a Majorana-type or Weyl-type spinor in a six-dimensional spacetime that reflects the intrinsic quantum numbers of chirality spin. A generalized Dirac equation is obtained in the six-dimensional spacetime with a maximal symmetry. Based on the framework of gravitational quantum field theory proposed in Ref. [1] with the postulate of gauge invariance and coordinate independence, we arrive at a maximally symmetric gravitational gauge field theory for the massless Dirac fermion in six-dimensional spacetime. Such a theory is governed by the local spin gauge symmetry SP(1,5) and the global Poincar′e symmetry P(1,5)= SO(1,5) P~(1,5) as well as the charge spin gauge symmetry SU(2). The theory leads to the prediction of doubly electrically charged bosons. A scalar field and conformal scaling gauge field are introduced to maintain both global and local conformal scaling symmetries. A generalized gravitational Dirac equation for the massless Dirac fermion is derived in the six-dimensional spacetime. The equations of motion for gauge fields are obtained with conserved currents in the presence of gravitational effects. The dynamics of the gauge-type gravifield as a Goldstone-like boson is shown to be governed by a conserved energy-momentum tensor, and its symmetric part provides a generalized Einstein equation of gravity. An alternative geometrical symmetry breaking mechanism for the mass generation of Dirac fermions is demonstrated.     

Bosonic symmetries of the Dirac equation

We have found on the basis of the symmetry analysis of the standard Dirac equation with nonzero mass the new physically meaningful features of this equation. The new bosonic symmetries of the Dirac equation in both the Foldy-Wouthuysen and the Pauli-Dirac representations are found, among which (together with the 32-dimensional pure matrix algebra of invariance) the new spin s=(1,0) multiplet Poincaré symmetry is proved. In order to carry out the corresponding proofs a 64-dimensional extended real Clifford-Dirac algebra is put into consideration.