MECÂNICA GRACELI GENERALIZADA - QUÂNTICA TENSORIAL DIMENSIONAL RELATIVISTA DE CAMPOS.
MECÃNICA GRACELI GERAL - QTDRC.
equação Graceli dimensional relativista tensorial quântica de campos G* = = [ / IFF ] G* = / G / .= / [DR] = = .= + G+ G* = = [ ] ω , , / T] / c [ [x,t] ] = |
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Teoria | Interação | mediador | Magnitude relativa | Comportamento | Faixa |
---|---|---|---|---|---|
Cromodinâmica | Força nuclear forte | Glúon | 1041 | 1/r7 | 1,4 × 10-15 m |
Eletrodinâmica | Força eletromagnética | Fóton | 1039 | 1/r2 | infinito |
Flavordinâmica | Força nuclear fraca | Bósons W e Z | 1029 | 1/r5 até 1/r7 | 10-18 m |
Geometrodinâmica | Força gravitacional | gráviton | 10 | 1/r2 | infinito |
G* = OPERADOR DE DIMENSÕES DE GRACELI.
DIMENSÕES DE GRACELI SÃO TODA FORMA DE TENSORES, ESTRUTURAS, ENERGIAS, ACOPLAMENTOS, , INTERAÇÕES DE CAMPOS E ENERGIAS, DISTRIBUIÇÕES ELETRÔNICAS, ESTADOS FÍSICOS, ESTADOS QUÂNTICOS, ESTADOS FÍSICOS DE ENERGIAS DE GRACELI, E OUTROS.
/
/ G* *= = [ ] ω , , .=
MECÂNICA GRACELI GENERALIZADA - QUÂNTICA TENSORIAL DIMENSIONAL RELATIVISTA DE INTERAÇÕES DE CAMPOS. EM ;
MECÂNICA GRACELI REPRESENTADA POR TRANSFORMADA.
dd = dd [G] = DERIVADA DE DIMENSÕES DE GRACELI.
- [ G* /. ] [ [
G { f [dd]} ´[d] G* . / f [d] G* dd [G]
O ESTADO QUÂNTICO DE GRACELI
- [ G* /. ] [ [ ]
G* = DIMENSÕES DE GRACELI TAMBÉM ESTÁ RELACIONADO COM INTERAÇÕES DE ENERGIAS, QUÂNTICAS, RELATIVÍSTICAS, , E INTERAÇÕES DE CAMPOS.
o tensor energia-momento é aquele de um campo eletromagnético,
Exchange symmetry or permutation symmetry
[edit]Bosons are particles whose wavefunction is symmetric under such an exchange or permutation, so if we swap the particles, the wavefunction does not change. Fermions are particles whose wavefunction is antisymmetric, so under such a swap the wavefunction gets a minus sign, meaning that the amplitude for two identical fermions to occupy the same state must be zero. This is the Pauli exclusion principle: two identical fermions cannot occupy the same state. This rule does not hold for bosons.
In quantum field theory, a state or a wavefunction is described by field operators operating on some basic state called the vacuum. In order for the operators to project out the symmetric or antisymmetric component of the creating wavefunction, they must have the appropriate commutation law. The operator
- / G* *= = [ ] ω , , .=
(with an operator and a numerical function with complex values) creates a two-particle state with wavefunction , and depending on the commutation properties of the fields, either only the antisymmetric parts or the symmetric parts matter.
Let us assume that and the two operators take place at the same time; more generally, they may have spacelike separation, as is explained hereafter.
If the fields commute, meaning that the following holds:
- / G* *= = [ ] ω , , .=
then only the symmetric part of contributes, so that , and the field will create bosonic particles.
On the other hand, if the fields anti-commute, meaning that has the property that
- / G* *= = [ ] ω , , .=
then only the antisymmetric part of contributes, so that , and the particles will be fermionic.
In physics, and especially quantum field theory, an auxiliary field is one whose equations of motion admit a single solution. Therefore, the Lagrangian describing such a field contains an algebraic quadratic term and an arbitrary linear term, while it contains no kinetic terms (derivatives of the field):
- / G* *= = [ ] ω , , .=
The equation of motion for is
- / G* *= = [ ] ω , , .=
and the Lagrangian becomes
- / G* *= = [ ] ω , , .=
Auxiliary fields generally do not propagate,[1] and hence the content of any theory can remain unchanged in many circumstances by adding such fields by hand. If we have an initial Lagrangian describing a field , then the Lagrangian describing both fields is
- / G* *= = [ ] ω , , .=
Therefore, auxiliary fields can be employed to cancel quadratic terms in in and linearize the action . / G* *= = [ ] ω , , .=
Examples of auxiliary fields are the complex scalar field F in a chiral superfield,[2] the real scalar field D in a vector superfield, the scalar field B in BRST and the field in the Hubbard–Stratonovich transformation.
The quantum mechanical effect of adding an auxiliary field is the same as the classical, since the path integral over such a field is Gaussian. To wit:
- / G* *= = [ ] ω , , .=
The Dirac equation in the form originally proposed by Dirac is:[7]: 291 [8] / G* *= = [ ] ω , , .= where ψ(x, t) is the wave function for an electron of rest mass m with spacetime coordinates x, t. p1, p2, p3 are the components of the momentum, understood to be the momentum operator in the Schrödinger equation. c is the speed of light, and ħ is the reduced Planck constant. These fundamental physical constants reflect special relativity and quantum mechanics, respectively.
Dirac's purpose in casting this equation was to explain the behavior of the relativistically moving electron, thus allowing the atom to be treated in a manner consistent with relativity. He hoped that the corrections introduced this way might have a bearing on the problem of atomic spectra.
Up until that time, attempts to make the old quantum theory of the atom compatible with the theory of relativity—which were based on discretizing the angular momentum stored in the electron's possibly non-circular orbit of the atomic nucleus—had failed, and the new quantum mechanics of Heisenberg, Pauli, Jordan, Schrödinger, and Dirac himself had not developed sufficiently to treat this problem. Although Dirac's original intentions were satisfied, his equation had far deeper implications for the structure of matter and introduced new mathematical classes of objects that are now essential elements of fundamental physics.
The new elements in this equation are the four 4 × 4 matrices α1, α2, α3 and β, and the four-component wave function ψ. There are four components in ψ because the evaluation of it at any given point in configuration space is a bispinor. It is interpreted as a superposition of a spin-up electron, a spin-down electron, a spin-up positron, and a spin-down positron.
The 4 × 4 matrices αk and β are all Hermitian and are involutory: / G* *= = [ ] ω , , .=
These matrices and the form of the wave function have a deep mathematical significance. The algebraic structure represented by the gamma matrices had been created some 50 years earlier by the English mathematician W. K. Clifford. In turn, Clifford's ideas had emerged from the mid-19th-century work of German mathematician Hermann Grassmann in his Lineare Ausdehnungslehre (Theory of Linear Expansion). [citation needed]
The single symbolic equation thus unravels into four coupled linear first-order partial differential equations for the four quantities that make up the wave function. The equation can be written more explicitly in Planck units as:[9]which makes it clearer that it is a set of four partial differential equations with four unknown functions.
Making the Schrödinger equation relativistic
[edit]The Dirac equation is superficially similar to the Schrödinger equation for a massive free particle:
/ G* *= = [ ] ω , , .=
Although it is not a successful relativistic generalization of the Schrödinger equation, this equation is resurrected in the context of quantum field theory, where it is known as the Klein–Gordon equation, and describes a spinless particle field (e.g. pi meson or Higgs boson). Historically, Schrödinger himself arrived at this equation before the one that bears his name but soon discarded it. In the context of quantum field theory, the indefinite density is understood to correspond to the charge density, which can be positive or negative, and not the probability density.
The left side represents the square of the momentum operator divided by twice the mass, which is the non-relativistic kinetic energy. Because relativity treats space and time as a whole, a relativistic generalization of this equation requires that space and time derivatives must enter symmetrically as they do in the Maxwell equations that govern the behavior of light — the equations must be differentially of the same order in space and time. In relativity, the momentum and the energies are the space and time parts of a spacetime vector, the four-momentum, and they are related by the relativistically invariant relation
which says that the length of this four-vector is proportional to the rest mass m. Substituting the operator equivalents of the energy and momentum from the Schrödinger theory produces the Klein–Gordon equation describing the propagation of waves, constructed from relativistically invariant objects, / G* *= = [ ] ω , , .=
with the wave function being a relativistic scalar: a complex number which has the same numerical value in all frames of reference. Space and time derivatives both enter to second order. This has a telling consequence for the interpretation of the equation. Because the equation is second order in the time derivative, one must specify initial values both of the wave function itself and of its first time-derivative in order to solve definite problems. Since both may be specified more or less arbitrarily, the wave function cannot maintain its former role of determining the probability density of finding the electron in a given state of motion. In the Schrödinger theory, the probability density is given by the positive definite expressionand this density is convected according to the probability current vector / G* *= = [ ] ω , , .=
with the conservation of probability current and density following from the continuity equation:
The fact that the density is positive definite and convected according to this continuity equation implies that one may integrate the density over a certain domain and set the total to 1, and this condition will be maintained by the conservation law. A proper relativistic theory with a probability density current must also share this feature. To maintain the notion of a convected density, one must generalize the Schrödinger expression of the density and current so that space and time derivatives again enter symmetrically in relation to the scalar wave function. The Schrödinger expression can be kept for the current, but the probability density must be replaced by the symmetrically formed expression[further explanation needed] / G* *= = [ ] ω , , .=
which now becomes the 4th component of a spacetime vector, and the entire probability 4-current density has the relativistically covariant expression
/ G* *= = [ ] ω , , .=
The continuity equation is as before. Everything is compatible with relativity now, but the expression for the density is no longer positive definite; the initial values of both ψ and ∂tψ may be freely chosen, and the density may thus become negative, something that is impossible for a legitimate probability density. Thus, one cannot get a simple generalization of the Schrödinger equation under the naive assumption that the wave function is a relativistic scalar, and the equation it satisfies, second order in time.
and they all mutually anti-commute: / G* *= = [ ] ω , , .=
In physics, the Majorana equation is a relativistic wave equation. It is named after the Italian physicist Ettore Majorana, who proposed it in 1937 as a means of describing fermions that are their own antiparticle.[1] Particles corresponding to this equation are termed Majorana particles, although that term now has a more expansive meaning, referring to any (possibly non-relativistic) fermionic particle that is its own anti-particle (and is therefore electrically neutral).
There have been proposals that massive neutrinos are described by Majorana particles; there are various extensions to the Standard Model that enable this. The article on Majorana particles presents status for the experimental searches, including details about neutrinos. This article focuses primarily on the mathematical development of the theory, with attention to its discrete and continuous symmetries. The discrete symmetries are charge conjugation, parity transformation and time reversal; the continuous symmetry is Lorentz invariance.
Charge conjugation plays an outsize role, as it is the key symmetry that allows the Majorana particles to be described as electrically neutral. A particularly remarkable aspect is that electrical neutrality allows several global phases to be freely chosen, one each for the left and right chiral fields. This implies that, without explicit constraints on these phases, the Majorana fields are naturally CP violating. Another aspect of electric neutrality is that the left and right chiral fields can be given distinct masses. That is, electric charge is a Lorentz invariant, and also a constant of motion; whereas chirality is a Lorentz invariant, but is not a constant of motion for massive fields. Electrically neutral fields are thus less constrained than charged fields. Under charge conjugation, the two free global phases appear in the mass terms (as they are Lorentz invariant), and so the Majorana mass is described by a complex matrix, rather than a single number. In short, the discrete symmetries of the Majorana equation are considerably more complicated than those for the Dirac equation, where the electrical charge symmetry constrains and removes these freedoms.
Definition
[edit]The Majorana equation can be written in several distinct forms:
- As the Dirac equation written so that the Dirac operator is purely Hermitian, thus giving purely real solutions.
- As an operator that relates a four-component spinor to its charge conjugate.
- As a 2×2 differential equation acting on a complex two-component spinor, resembling the Weyl equation with a properly Lorentz covariant mass term.[2][3][4][5]
These three forms are equivalent, and can be derived from one-another. Each offers slightly different insight into the nature of the equation. The first form emphasises that purely real solutions can be found. The second form clarifies the role of charge conjugation. The third form provides the most direct contact with the representation theory of the Lorentz group.
Purely real four-component form
[edit]The conventional starting point is to state that "the Dirac equation can be written in Hermitian form", when the gamma matrices are taken in the Majorana representation. The Dirac equation is then written as[6]
- / G* *= = [ ] ω , , .=
with being purely real 4×4 symmetric matrices, and being purely imaginary skew-symmetric; as required to ensure that the operator (that part inside the parentheses) is Hermitian. In this case, purely real 4‑spinor solutions to the equation can be found; these are the Majorana spinors.
Charge-conjugate four-component form
[edit]The Majorana equation is
- / G* *= = [ ] ω , , .=
with the derivative operator written in Feynman slash notation to include the gamma matrices as well as a summation over the spinor components. The spinor is the charge conjugate of By construction, charge conjugates are necessarily given by
- / G* *= = [ ] ω , , .=
where denotes the transpose, is an arbitrary phase factor conventionally taken as and is a 4×4 matrix, the charge conjugation matrix. The matrix representation of depends on the choice of the representation of the gamma matrices. By convention, the conjugate spinor is written as
- / G* *= = [ ] ω , , .=
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