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Supplemental Material
8-dimensional SpaceTime is Parallelizable RP1 x S7
and
4-dim Physical SpaceTime is Parallelizable RP1 x S3.
These SpaceTimes have Parallel Transport 1-form Connections with zero
Curvature:
1-form A - Connection
The Connection 1-form is also called the Gauge Potential.
2-form dA - Curvature
The Curvature 2-form is a (0,2)-tensor,
is a Covariant Derivative of the Connection 1-form,
and is defined by
2
___
considering a parallelogram 1 /__/ 4
3
Curvature is defined by parallel transport
of a vector C in two ways, and taking the difference:
___
First transport C along 1 and then 2, by path /
Then transport C along 3 and then 4, by path __/
Curvature is the difference between the two,
C transported along 12 and C transported along 34.
Note that in both cases C is, after transportation,
in a well-defined tangent space because the parallelogram is closed.
These Parallel Transport 1-form Connections have Affine Torsion that give
Structure Constants for Lie Algebras of Gauge Groups:
3-form A /\ dA - Affine
Torsion
To define Affine Torsion
(Affine Torsion as opposed to Topological Torsion),
a (1,2)-tensor which is
the antisymmetric part of the Connection,
start with two vectors A __ and B / at an origin point.
___
First parallel transport B along A to get a vector /
Then parallel transport A along B to get a vector __/
For a manifold with no Torsion,
the end points are the same and when you make a parallelogram
out of the two paths AB and BA, the parallelogram closes,
and you might say that AB - BA = 0.
For parallelizable manifolds,
such as non-abelian Lie groups and S3 and S7,
your parallel transport connection can have zero curvature
but non-zero Afffine Torsion. Affine Torsion gives you
the structure constants of Lie algebras,
for the cases of Lie groups and S3.
Since RP1 is topologically equivalent to
the 1-sphere S1 = U(1) = unit Complex Numbers,
the U(1) Complex phase of particle propagators can
be associated with the Time RP1 of SpaceTime.
Since RP1 is 1-dimensional and U(1) is Abelian,
the associated Affine Torsion is zero.
For S7, Torsion varies with the position on the 7-sphere S7,
so you have to take that into account by considering
that the transport of B along A ends at one point on the S7
and
the transport of A along B ends at a different point on the S7
so that
the one of the two point tangent spaces must be mapped to the other.
Such a map has two parts:
the map from one end point to the other can be thought
of as a path on a second S7 7-sphere;
and
the map from one tangent space to the other can be thought
of as an element of the 14-dim Lie group G2 that is
the automorphism group of the octonions.
Therefore,
to make a Lie group from S7 using its Torsion,
you have to combine (non-trivially) two S7 7-spheres with G2,
producing the 7+1+14 = 28-dim Lie group Spin(8) that
is the double cover of the 8-dim rotation group SO(8).
In the D4-D5-E6-E7 physics model
SpaceTime is parallelizable RP1 x S7..
The 28 infinitesimal generators of Spin(8)
correspond to
l6 U(2,2) gauge bosons that produce Gravity and the Higgs Mechanism
plus
12 gauge bosons of the Standard Model.
Click here
to see the Cohomology Structure of Spin(8).
All 28 of the Spin(8) generators can be associated
with Affine Torsion of the Space S7 of RP1 x S7 SpaceTime.
Since U(2,2) = U(1) x SU(2,2),
the Space part of the U(1) Complex phase of particle propagators
and to
the Conformal Group Spin(2,4) = SU(2,2) with 15 generators:
1 Dilation;
4 Special Conformal Transformations (Non-linear Mobius Fractional
Projective Transformations);
3 Rotations plus 3 Boosts; and
4 Translations.
The 4 Translations and 3 Rotations plus 3 Boosts
form the 10-dimensional anti-deSitter group Spin(2,3) that produces Gravity by
the MacDowell-Mansouri Mechanism as described by Freund in Chapter 21 of his
book Introduction to Supersymmetry (Cambridge 1986), saying: "... [if we do not
assume space-inversion invariance] we could have ... a parity-violating gravity.
This would [produce] ... solutions of the gravitational field equations without
definite space-inversion properties. ... Unlike in Einstein's theory, ... [the
MacDowell-Mansouri Mechanism] ... does not require the Riemannian invertibility
of the metric. ... [The MacDowell-Mansouri Mechanism] is wider in scope than the
ordinary Hilbert-Einstein formulation. ... the solution has torsion ... produced
by an interference between parity violating and parity conserving amplitudes.
Parity violation and torsion go hand-in-hand. ...".
The Parity-Violating Gravitational Torsion described by
Freund is different from the Affine Torsion that gives the Structure
Constants of the Lie Algebras of the Gauge Groups. Like Einstein's
Gravitational Curvature of SpaceTime, the Gravitational Torsion of SpaceTime
is an Effective Deformation of 4-dim Physical SpaceTime in which 4-dim
Physical SpaceTime effectively appears to be, not an immutable RP1 x S3, but a
Compressible
Aether.
The Gravitational Torsion is NOT fixed by the theory to be the
gravitational constant G, as pointed out by Ivanenko
and Saradanashvily, in Physics Reports 94 (1983) 1-45, where they say:
"... the gravitation Lg [and] the torsion Ls ... components of a total
Lagrangian may be chosen independently of each other, e.g. Lg is the
Hilbert-Einstein Lagrangian of [General Relativity, but] ... Ls ...[could be
a] Lagrangian of the Yang-Mills type. ... nothing requires that coupling
constants of the torsion ... coincide with the gravitation constant ... In
particular, torsion ... coupling constants may be chosen much stronger than
the gravitational one, which opens the door to the hypothesis about the
possibility of strong torsion ... whose effect would be comparable with
weak or strong interaction effects. ...".
The 4 Special
Conformal Transformations (Non-linear Mobius Fractional Projective
Transformations) preserve discontinuities, signals, and other properties of
characteristics that are not restricted to a finite propagation speed. They
correspond to the Conformal
GraviPhotons.
R. M.
Kiehn says: "... in 1932, V. Fock ... deduced the characteristic system
for the solutions of Maxwell's equations which are not unique in a
neighborhood. He clearly formulated the idea that electromagnetic signals were
propagating discontinuities. ... Mappings which preserved the eikonal, taking
a discontinuity in E field to a discontinuity, were of two and only two types.
... A linear type which Fock proved was the Lorentz group of transformations
... for which a finite propagation speed is an invariant concept. ...and a
non-linear transformation group (the Moebius fractional projective
transformations) which also preserve discontinuities, signals, and other
properties of characteristics. Such signals are not restricted to a finite
propagation speed. .... the propagation speed of the singularity can be
anything - including infinity. !!! ... In optically active media, the
propagation speed of the discontinuities is faster or slower that the speed of
light, depending on the whether or not the helicity (circular polarization) is
aligned or anti-aligned with the optical axis. ...".
William D. Walker, in
physics/0001063, has shown "... that electromagnetic near-field waves and
wave groups, generated by an oscillating electric dipole, propagate much
faster than the speed of light as they are generated near the source, and
reduce to the speed of light at about one wavelength from the source. The
speed at which wave groups propagate (group speed) is shown to be the speed at
which both modulated wave information and wave energy density propagate.
Because of the similarity of the governing partial differential equations, two
other physical systems (magnetic oscillating dipole, and gravitational
radiating oscillating mass) are noted to have similar results. ...".
The 1 Dilation
can be fixed to set a Mass/Energy scale, such as the Vacuum Expectation Value of
the Higgs Mechanism (about 250 GeV), which is equivalent to setting the
Compressibility of the Aether, which in turn allows longitudinal degrees of
freedom such as the Mass of SU(2) Weak Bosons.
The Dilation sets
the scale of the Higgs VeV at 250 GeV so that general deformations of
SpaceTime can take place only above that energy level, while GraviPhoton
Special Conformal (Hopf
flow) transformations are useful in Conformal deformations of SpaceTime.
Incompressibility
of the Aether below 250 GeV is only with respect to the 6-dim vector space
of the Conformal Group
Spin(2,4), so that below 250 GeV you can see Conformal phenomena that
appear to show compressibility from the point of view of 3-dim space or 4-dim
Minkowski spacetime. Such conformal phenomena include the Fock superluminal
solutions of Maxwell's equations that are described by R. M.
Kiehn.
The 4
GraviPhoton Special Conformal transformations are like the Moebius linear
fractional transformations, that do deform Minkowski spacetime but take
hyperboloids into hyperboloids and are the symmetries of superluminal
solutions of the Maxwell equations. They are incompressible/linear from the
point of view of a 6-dimensional SpaceTime, with 4 spatial dimensions and 2
time dimensions, because the conformal group over Minkowski spacetime is just
SU(2,2) = Spin(2,4), the covering group of SO(2,4), and therefore the Lie
algebra generators look like those of rotations in a 6-dim vector space of
signature (2,4). This is the 4-dim space with 2-dim time suggested by Robert
Neil Boyd, in which things look linear (even though from our conventional
3-dim spatial or 4-dim Minkowski point of view they might appear, due to our
limited conventional perspective, to be nonlinear). If you regard Physical SpaceTime
as the 6-dimensional vector space of Spin(2,4), and Internal Symmetry Space
as 4-dimensional CP2, then the total space is
6+4=10-dimensional. With respect to tthe D4-D5-E6-E7
model, that 10-dim space corresponds:
to the 10-dim vector space of the D5 Lie
Algebra Spin(2,8); and
to the 10-dim element of the decomposition of the 27-dim representation
of the E6 Lie
Algebra into 10 + 16 + 1 under its D5 subalgebra (see, for example, Lie
Algebras in Particle Physics, 2nd edition, by Howard Georgi, Perseus Books
(1999), page 308).
From the compact version Spin(6) = SU(4) of the Conformal Group Spin(2,4) =
SU(2,2) and its coset space with respect to Spin(5) (the compact version of the
anti-deSitter group Spin(2,3)),
Spin(6) / Spin(5) = SU(4) / Sp(2) = the 5-sphere S5 and from the
fibration S1 -> S5 -> CP2
it appears that, in the D4-D5-E6-E7 physics
model, the 4-dim Special Conformal Transformations correspond to the 4-dim
Internal Symmetry Space CP2 and the 1-dim Dilation corresponds to the RP1
(topologically equivalent to S1) Time of SpaceTime.
Since the Standard Model is SU(3) x SU(2) x U(1),
the Gauge Group Generators,
represented in the 4-dim Internal Symmetry Space CP2 = SU(3)/U(2)
of the D4-D5-E6-E7 physics model, of:
8-dim Color Force SU(3) acting globally in CP2,
and locally in 4-dim Physical SpaceTime,
where Color SU(3) is confined;
4-dim ElectroWeak U(2) acting locally in CP2
and also locally in 4-dim Physical SpaceTime.
Since U(2) = U(1) x SU(2) = S1 x S3, with U(1) = S1 for Electromagnetism and
SU(2) = S3 for the Weak Force:
With respect to the 4-dim Physical SpaceTime RP1 x S3:
Since S1 = Spin(2) = U(1) = unit Complex Numbers,
photons of U(1) Electromagnetism can be associated with
their own U(1) propagator phase. Since U(1) is Abelian,
it is associated with zero Affine Torsion.
Since S3 = Spin(3) = SU(2) = Sp(1) = unit Quaternions,
the SU(2) Weak Force can be associated with
non-zero Affine Torsion of the Space S3 of 4-dim Physical SpaceTime,
which would be inherited from
the Affine Torsion of the Space S7 of 8-dim SpaceTime.
Since RP1 is topologically equivalent to S1,
U(2) is topologically equivalent to 4-dim Physical SpaceTime RP1 x S3.
The action of Gravity on the
4-dim Physical SpaceTime RP1 x S3 to produce Gravitational Curvature and
Gravitational Torsion corresponds to the action of the Higgs Mechanism on
the Affine Torsion ElectroWeak U(2) Gauge Bosons to give them mass.
The coupling of Gravitational Torsion to Dirac Spinor Fermion
Particles and Antiparticles acts as a Yukawa Coupling to give them mass.
At tree level, the Yukawa Coupling gives no mass to the Weyl Fermion Neutrinos
and Antineutrinos, which are related by triality to the RP1 of Time and not to
the Space S7 of SpaceTime, which are associated with the massless photons of S1
= U(1) Electromagnetism and the massive Weak Bosons of the S3 = SU(2) Weak Force
and the Higgs Mechanism, respectively.
4-form dA /\ dA - HyperVolume
In American Journal of Physics 39 (1971) 901-904,
David Finkelstein showed that in Unimodular Relativity
the Cosmological Constant is an unavoidable Lagrange
Multiplier beloging to a constraint that expresses
the existence of a Fundamental Volume Element of
Spacetime Hypervolume at every point of Spacetime.
Unimodular SL(4) is related to SU(2,2) which is
isomorphic to the Conformal Group Spin(2,4).
Ivanenko and Saradanashvily,
in Physics Reports 94 (1983) 1-45, say:
"... the gravitation Lg [and] the torsion Ls ... components of a total
Lagrangian may be chosen independently of each other, e.g. Lg is the
Hilbert-Einstein Lagrangian of [General Relativity, but] ... Ls ...[could be a]
Lagrangian of the Yang-Mills type. ... nothing requires that coupling constants
of the torsion ... coincide with the gravitation constant ... In particular, torsion
... coupling constants may be chosen much stronger than the gravitational
one, which opens the door to the hypothesis about the possibility of
strong torsion ... whose effect would be comparable with weak or strong
interaction effects. ...
In recent years torsion has attracted great attention ... The reason that
torsion comes to the front lies in the fact that at present we only know two
observable space-time characteristics of particles, namely, mass
(energy-momentum) and spin. And just energy-momentum and spin of matter turn out
to be the sources of metric gravity and torsion, respectively. But because we do
not observe any object possessing macrovalues of spin polarization, torsion
theory as yet cannot rival with Einstein's theory. ...
Let us consider a system of Dirac massless fermions ... in the
Einstein-Cartan space ... one finds ... the familiar Einstein gravitation
equation, but with the modified right hand side corresponding to the
energy-momentum tensor of nonlinear fermions ... representing the non-linear
generalization of the Dirac equation ... due to torsion ... Non-linearities due
to torsion arise in other fields of non-vanishing spin, e.g. in electromagnetic
... fields ... At the same time, the question of torsion interaction with gauge
fields is not quite yet clear as yet because such an interaction breaks the
correspondiing gauge invariance. ...
Another interesting phenomenon ... is that vacuum polarization due to
quantized spinor matter induces quadratic terms in the Lagrangian of the
Einstein-Cartan field quite like the well-known case of the Einstein gravity
field (in the last case such terms can lead to non-singular de-Sitter type
inflationary cosmology. The calculation of the one-loop corrections leads to the
appearance of counterterms in the Lagrangian, which have the form of the
quadratic torsion Lagrangian ... Such phenomena attract attention as a possible
mechanism of the origin of induced gravitation and other gauge fields by
interactions of matter fields. ...".
Saul-Paul Sirag says, about torsion and curvature:
"... if a space is curved, it is impossible to compare two distant vectors
without some method of parallel transport of vectors throughout the curved
space. The amount of curvature is a measure of the mismatch of a vector with a
copy of itself which has undergone a complete circuit. ... The parallel
transport is provided by a structure which is added to the manifold and is
called the connection. In the theory of general relativity, the
connection is provided by an object calledthe Christoffel symbol G_ij^k. This is
a very compact notation for a set of 40 (= 64 -24) functions on the 4-d
spacetime. If the symbol carried two asymmetric lower indices, there would be 64
(= 4 x 4 x 4) functions; but the symmetry of the lower indices reduces the
independent functions to 40. The standard Christoffel symbol of general
relativity is symmetric in the two lower indicies i,j, and generates a
connection called the Levi-Civita connection. However, there are geometries
for which an asymmetic Christoffel symbol is employed in addition to the the
symmetric Christoffel symbol. The asymmetry is carried by a tensor T called
the torsion. We can write:
G_ij^k - G_ji^k = T_ij^k
Thus although the Christoffel symbols are not tensors, their difference is a
tensor. In physics, we expect tensors to correspond to measurable quantities. If
T is 0, then the torsion is zero, and the symbol must be symmetric. A very
special case of parallel transport is called absolute parallelism. While
ordinary parallel transport guarantees that the vectors will be rotated only by
the curvature along the particular path in the circuit, an absolute
parallelism connection guarantees that the vectors will remain unrotated by
travel along any circuit that follows vector field flow lines. This implies that
there is no curvature for this absolute parallelism connection. However [there]
will, in general, be a gap in this circuit caused by a "vertical" motion of the
... moving vector. After making the ciruit, the moving vector and its
stay-at-home twin will, end up parallel to each other but separated by this
"vertical" gap. This gap is called the torsion. ... The connection
structure which provides curvature, is based on the symmetric Christoffel
symbol. Thus this connection (called the Levi-Civita connection) has zero
torsion. By contrast, the absolute parallelism connection which provides
torsion has zero curvature. ... there are good examples
of spaces carrying both these connections. These spaces are Lie group manifolds.
In fact, later work by Joseph Wolf proved that the only spaces that carry an
absolute parallelism (Cartan) connection are Lie groups--with one exception:
the
seven-sphere S7. ... the only spheres that carry an absolute parallelism
are spheres of dimension 1, 3, and 7. And the only spheres that are Lie groups
are spheres of dimensions 1 & 3. The Lie group structures of these spheres
are called U(1) and SU(2). Moreover, S1 (= U(1)) is the set of all unit complex
numbers, while S3 (= SU(2)) is the set of all unit quaternions, and S7 is the
set of all unit octonions (or Cayley numbers); it is because octonions are not
an associative algebra that S7 fails to be a Lie group; but the
octonion structure provides an absolute parallelism on S7. ... it is the
left-invariance (or right invariance) of the Lie algebra vector fields the
provides absolute parallelism. As Cartan discovered, there are three canonical
connections on a Lie group manifold. These three connections are generated by
three different actions of the Lie group on itself:
(1) Left action: g --> h g (where g and h are group elements of
Lie group G)
(2) Right action: g --> g h [(where g and h are group elements of Lie
group G)]
(3) Adjoint action: g --> h^(-1) gh (where h^(-1) is the inverse element
of h )
... The set of all ... tangent planes together form a vector bundle called
the tangent bundle of the Lie group. For the Lie group G, the symbol for the
tangent bundle is TG, and it is simply the direct product of the Lie group G and
the Lie algebra g. ... In contrast to the case of an ordinary manifold, which is
not a Lie group, we say that TG is a trivial bundle because it is direct
product of the base space G with the the fiber g, this implies a global
trivialization of the bundle structure; moreover, this global trivialization
corresponds to the absolute parallelism afforded by the group action on
the group manifold and thus on the parallel transport of vectors of the Lie
algebra, as described above. The intimate relationship between the Lie group G
and the Lie algebra g, has the consequence that the torsion of G ... is
simply the Lie product, [x,y], of g ... for the torsion T of a Lie group
manifold we can write:
[ X_i ,Y_j ] = T_ij^k Z^k
... where the componets of T are the structure constants of the Lie algebra;
and X, Y, and Zare Lie algebra elements, i.e., left-invariant vector fields on
G. For right invariant vector fields the torsion tensor is the would be -T_ij^k.
... In general, the curvature tensor describing the curvature of the Lie group
manifold is the Riemann curvature tensor which can be written in terms of the
Lie algebra structure constants:
R_i,kl^k = (1/4) C_hi^j C_kl^ h
The Riemann curvature tensor is the tensor generated by the Levi-Civita
connection, for which there is zero torsion. Thus on the Lie group manifolds
we have two radically different connections: the Cartan asymmetric connection
which has torsion but no curvature, and the symmetric Levi-Civita connection
which has curvature but no torsion. Given two connections on the same
manifold, the difference between the Christoffel symbols is a tensor, called the
difference tensor. In the case of these two connections on a Lie group manifold
the difference tensor is the contorsion tensor K.
We can write:
K_ij^k = G_ij^k - G_ij^k
where the first Christoffel symbol is the Cartan connection of absolute
parallelism (with 64 independent functions); the second ... Christoffel symbol
is the Levi-Civita connection (with 40 independent functions ...); and K is the
contorsion tensor (with 24 independent functions). The contorsion tensor is also
the tensor of Ricci rotation coefficients. ...".
Click here to download
the full .pdf 15 April 2000 article by Saul-Paul Sirag about Torsion and
Curvature.
Rainich, Wheeler, Misner, and Vaz and Rodrigues, have shown
how to get classical Electromagnetism as well as General Relativity from
Topology plus Metric. See the paper of Vaz and Rodrigues
Rodrigues (and Vaz)
have shown that the Electromagnetism of Maxwell and Dirac has SuperLuminal
solutions.
Lu has shown
experimentally, with sound, how to construct SuperLuminal solutions (in his
experiments, the speed of sound is analogous to the speed of light). Lu calls
these SuperLuminal solutions X waves.
SuperLuminal solutions have obvious uses in information
transmission.
Some unconventional SubLuminal solutions may have uses that relate
Electromagnetism to SpaceTime curvature, or, with respect to sound, perhaps
sonoluminescence.
The Conformal
Structure of Electromagnetism and Acoustic Waves is related to Physical
Wavelets.
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