Relationship between Conformal Geometrodynamics Equations and Dirac - PowerPoint PPT Presentation

Relationship between Conformal Geometrodynamics Equations and Dirac Equation M.V.Gorbatenko Russian Federal Nuclear Center – All-Russian Research Institute of Experimental Physics, Sarov, N.Novgorod region; E-mail: gorbatenko@vniief.ru Based on arXiv e-print 1002.2748 [gr-qc]

Subject of Discussion: What is Conformal Geometrodynamics (CGD) understood to mean? I Minimum conformally invariant extension of GR equations. CGD equations in flat space in terms of vector and anti-symmetric second-rank tensor. Algebraic mapping of a set of tensors II {scalar, pseudoscalar, vector, pseudovector, anti-symmetric second-rank tensor} to a set of four complex bispinors {bispinor matrix}. Main Statement: Dynamics of a set of tensors {vector, anti-symmetric second-rank tensor} governed III by CGD equations can be mapped to the dynamics of a set of four real bispinors {bispinor matrix} governed by the Dirac equation. 2

Properties of Conformal Transformations Conformal transformations are the best candidates to play the role of the base group of transformations for the extension of GR equations. The best because conformal transformations are the transformations that preserve cause and effect relations between events. The conformal transformations include inversion transformations, i.e. transformations that can lead to relations between solutions that describe macro- and micro-scale processes. 3

What is "Conformal Geometrodynamics"? CGD equations have the form of equations of General Relativity 1 − = R g R T αβ αβ αβ 2 in which the energy-momentum tensor has a specific structure ν 2 = − − − + + + λ T 2 A A g A 2 g A A A g αβ α β αβ αβ ν α β β α αβ ; ; ; CGD equations are invariant with respect to conformal transformations σ − σ 2 2 → ⋅ → − σ λ → λ ⋅ g g e , A A , e αβ αβ α α α ; 4

Properties of CGD Equations 1) For them, the Cauchy problem is defined without links to Cauchy data on the initial hypersurface. µ µ = T 0 2) They lead to the equations , which in turn lead α ; ≡ λ − λ to the existence of the vector , satisfying the relationship 2 J A α α α , J α . α = 0 ; J α 3) The presence of the vector allows us to introduce, using the Eckart method, thermodynamic functions of state of geometrodynamic continuum: energy density, pressure, specific volume, viscosity coefficient, heat conductivity coefficient, entropy density, temperature. 5

CGD Equations in Flat Space Equations that follow strictly from CGD equations µ µ = 0 T α ; in flat space: ( ) − = ⋅ J J 4 m H (1) β α α β αβ , , ν = − ⋅ H m J (2) α ν α ; (3) ν ν = = J 0 m Const ; 6

Algorithm for Bispinor Mapping to Tensors Direct problem: ψ We have a bispinor . We seek tensor quantities generated by the bispinor. Solution: 1Sp { } + = ψ ψ a D 1)Scalar 4 i { } + = − ψ γ ψ 2)Pseudoscalar b Sp D 5 4 1Sp 3)Vector { } α + α = ψ γ ψ j D 4 i 4)Pseudovector { } α + α = − ψ γ γ ψ s Sp D 5 4 1Sp 5)Antisymmetric tensor { } + = − ψ ψ h DS αβ αβ 8 7

Algorithm for Tensor Mapping to Bispinors Inverse problem: At the point of Riemann space, we have arbitrarily defined tensor quantities: 1)Scalar a b 2)Pseudoscalar j α 3)Vector s α 4)Pseudovector h αβ 5)Antisymmetric tensor We seek a set of bispinors reproducing this set of tensor quantities. 8

Formalism of Dirac Matrices γ γ + γ γ = 2 g Definition of Dirac matrix: α β β α αβ − + 1 γ = − γ D D Anti-hermitizing matrix: µ µ Z Bispinor matrix: ⎫ ∇ = − Γ Z Z Z ⎪ Operation of covariant α α α ; ⎬ differentiation: + + + ∇ = + Γ ⎪ Z Z Z ⎭ α α α ; ( ) ν γ ∇ = ⋅ Z m Z Dirac equation: ν 9

Solving the Inverse Problem with Defined Vector and Antisymmetric Tensor 1) Based on the vector and antisymmetric tensor, construct the matrix M: ( ) ( ) α − µν − 1 1 = ⋅ γ + ⋅ M j D h S D α µν 2) Calculate eigenvalues of M . 3) If the matrix M is positively defined, extract "square root" from it. ZZ + = M Z The matrix is a direct sum of four real bispinors reproducing the j α h αβ given quantities and . 1Sp { } 1Sp + { } ≡ γ + j Z D Z ≡ − h Z DS Z α α αβ αβ 4 8 10

Summary on the Algorithm for Tensor Mapping to Bispinors The algorithm provides for the following operations: (1) Construct the matrix M . The resulting matrix automatically turns out to be Hermitian and, consequently, having real eigenvalues or pairs of complex- conjugate ones. (2) Calculate eigenvalues of the matrix M . Find regions in space, where all eigenvalues of the matrix M are positive. (3) Extract the positive “square root” of the matrix M in these regions of space. Subject to the additional positivity condition, the resulting matrix Z is found uniquely, and it is the proper matrix, which reproduces the field of the vector j α and anti-symmetric tensor h αβ using the formulas shown at the bot- tom of the slide. This mapping procedure is algebraic and valid at any point for the fields j α , h αβ irrespective of whether or not they are governed by some equations or are arbitrary. 11

What happens with the quantities , if the bispinor matrix satisfies α αβ j , h the Dirac equation j α α = 0 ; 1 { } ( ) ( ) ( ) ν + µ + µ − = ⋅ + ∇ γ γ − γ γ ∇ j j 4 m h E Sp Z D Z Z D Z β α α β αβ αβµ ν ν , , 5 5 4 1Sp ( ) ( ) ( ) ν + + =− ⋅ − ∇ − ∇ h m j Z DZ Z D Z α ν α α α ; 8 1 Sp { } ( ) ( ) λαβε λ + + λ = ⋅ ∇ γ − γ ∇ E h Z D Z Z D Z αβ ε ; 5 5 4 12

Comparison of equations αβ α J , H CGD equations for Consequences of Dirac equation for j , h α αβ j α J α α = α = 0 0 ; ; ( ) ( ) − = ⋅ + − = j j 4 m h J J 4 mH β α α β αβ , , β α α β αβ ; ; 1Sp { } ( ) ( ) ν + µ + µ + ∇ γ γ − γ γ ∇ E Z D Z Z D Z αβµ ν ν 5 5 4 β ν = − ⋅ = − ⋅ H m J h m j α ν α α ⋅ ; β α ; 1Sp ( ) ( ) ( ) + + − ∇ − ∇ Z DZ Z D Z α α 8 αβµν 1 Sp βµ ν ≡ { } E H 0 ( ) ( ) λαβε λ + + λ = ⋅ ∇ γ − γ ∇ E h Z D Z Z D Z , αβ ε ; 5 5 4 1Sp { } + ≡ γ j Z D Z α α 4 J , H - Quantities, α αβ 1Sp included in CGD { } + ≡ − h Z DS Z αβ αβ equations 8 13

Main Statement H αβ J α Assume we have defined quantities and , satisfying (1) (2) (3) Z the equations , and (see slide 10) , and the matrix constructed at each point and satisfying the relationship ( ) ( ) + α − αβ − 1 1 = ⋅ γ + ⋅ ZZ J D H S D α αβ Z Then, the matrix satisfies the Dirac equation ( ) ν γ ∇ = ⋅ Z m Z , ν 1 ( ) ( ) ( ) − + − + 1 1 Γ = − Z Z Z Z Γ if the connectivity has the form . α α α , , α 2 If the connectivity has the above form, all spur terms, which disturb the consistency of the two dynamics, are removed, and during gauge transformation, the connectivity itself transforms according to the law standard for the gauge field. The connectivity corresponds to the gauge group O(4). 14

Other Formulation of the Main Result J α H αβ If the vector and the tensor are governed by CGD equations, and j α h if they initially coincide with the vector and tensor , αβ Z constructed based on the bispinor matrix , and if the bispinor connectivity in the chosen gauge is found from the rule 1 ( ) ( ) ( ) − + − + 1 1 Γ = − Z Z Z Z , α α α , , 2 then the equalities α α = j J = h H , , αβ αβ Z will also be satisfied at any time, and the matrix will satisfy the Dirac equation ( ) ν γ ∇ = ⋅ Z m Z ν . 15

What do the Obtained R es ults Mean? Range of Concordance of the Equations Conformally Dirac Equation. Invariant Gauge Fields Generalization of GR General Standard Model (SM) Relativity (GR) 16

Reasonable Hypothesis I CGD T • The geometrodynamics energy-momentum tensor αβ can model any tensor GR T αβ , which is used in GR to describe any type of matter. This is associated with the possibility of defining the Cauchy problem for CGD equations without links to the Cauchy data on the initial surface. • However, the modeling is approximate, as it is possible in a finite time span in a spatial domain of finite dimensions. The hypothesis was validated by expansions of centrally symmetric solutions and solutions for Friedman models. 17