5,958 research outputs found
Gauge invariant method for maximum simplification of the field strength in non-Abelian Yang-Mills theories
A new local gauge invariant method is introduced in order to maximally
simplify the expression for a SU(2) non-Abelian field strength. The new tetrads
introduced in previous works are going to play a fundamental role in the
algorithm presented in this manuscript. Three new local gauge invariant objects
are going to guide us through the process of making a field strength block
diagonal. The process is also covariant. Any non-trivial isospace field
strength projection will become block diagonal through this algorithm. Along
with the local gauge invariant method already developed in order to diagonalize
the stress-energy tensor, we have with this new local gauge invariant method to
maximally simplify the field strength, a new gauge invariant method to classify
Yang-Mills field theories.Comment: 17 pages, no figures. arXiv admin note: substantial text overlap with
arXiv:gr-qc/060204
Second proof for SU(2) isomorphic to LB1 X LB1 X LB1 theorem
In this note we present a second independent proof for the theorem introduced
previously that establishes an isomorphism between SU(2) and LB1 X LB1 X LB1.
Since the local groups LB1 and LB2 are isomorphic, it was also previously
proved a similar result for LB2 X LB2 X LB2. We are going to reverse the three
sets of tetrads that are going to be used in order to prove this new version.
Instead of choosing three SU(2) different tetrads keeping the electromagnetic
tetrad the same for all three sets of SU(2) tetrads, we are going to keep fixed
the SU(2) tetrad, that is, we are going to pick just one SU(2) tetrad but
choose three different arbitrary but fixed electromagnetic tetrads in order to
gauge locally the only local SU(2) tetrad involved in our new version of this
theorem. The same result will be obtained via an alternative but equivalent
way.Comment: A new and straightforward version of the theorem presented in
"Tetrads in Yang-Mills geometrodynamics
Dynamical symmetry breaking in non-Abelian geometrodynamics
We are going to analyze through a first order perturbative formulation the
local loss of symmetry when a source of non-Abelian Yang-Mills and
gravitational fields interacts with an external agent that perturbes the
original geometry associated to the source. Then, as the symmetry in Abelian
and non-Abelian field structures in four-dimensional Lorentzian spacetimes is
displayed through the existence of local orthogonal planes of symmetry that we
previously called blades one and two, the loss of symmetry will be manifested
by the tilting of these planes under the influence of the external agent. It
was found already that there is an algorithm to block diagonalize the
Yang-Mills field strength isospace projections in a local gauge invariant way.
Independently, it was also found an algorithm to diagonalize the Yang-Mills
stress-energy tensor in a gauge invariant way. Using these results and
perturbative analysis from a previous manuscript dealing with the Abelian case,
we are going to demonstrate how to develop an algorithm for constructing local
energy-momentum conserved currents inside both local orthogonal planes. As the
interaction proceeds, the planes are going to tilt perturbatively, and in this
strict sense the original local symmetries will be lost. But we will prove that
the new blades at the same point will correspond after the tilting generated by
perturbation, to new symmetries, with associated new local currents, both on
each new local planes of symmetry. Old symmetries will be broken, new will
arise. There will be a local symmetry evolution in the non-Abelian case as
well.Comment: arXiv admin note: substantial text overlap with arXiv:1306.0602,
arXiv:1306.2174, arXiv:gr-qc/060204
Dynamical symmetry breaking in geometrodynamics
We are going to analyze through a first order perturbative formulation the
local loss of symmetry when a source of electromagnetic and gravitational field
interacts with an agent that perturbes the original geometry associated to the
source. As the symmetry in Abelian or even non-Abelian field structures in four
dimensional Lorentzian spacetimes is displayed through the existence of local
planes of symmetry that we previously called blades one and two, the loss of
symmetry will be manifested by the tilting of these planes under the influence
of the external agent. In this strict sense the original local symmetry will be
lost. But we will prove that the new blades at the same point will correspond
after the tilting generated by perturbation to a new symmetry. The point of
this note is to prove that the geometrical manifestation of local gauge
symmetries is dynamic. The local original symmetries will be lost, nonetheless
new symmetries will arise. There is a dynamic evolution of local symmetries.Comment: Several modifications and corrections have been implemented in
sections (3) and (7
The equivalence between local inertial frames and electromagnetic gauge in Einstein-Maxwell theories
We are going to prove that locally the inertial frames and gauge states of
the electromagnetic field are equivalent. This proof will be valid for
Einstein-Maxwell theories in four-dimensional Lorentzian spacetimes. Use will
be made of theorems proved in a previous manuscript. These theorems state that
locally the group of electromagnetic gauge transformations is isomorphic to the
local Lorentz transformations of a special set of tetrad vectors. The tetrad
that locally and covariantly diagonalizes any non-null electromagnetic
stress-energy tensor. Two isomorphisms, one for each plane defined locally by
two separate sets of two vectors each. In particular, we are going to use the
plane defined by the timelike and one spacelike vector, plane or blade one.
These results will be extended to any tetrad that results in a local Lorentz
transformation of the special tetrad that locally and covariantly diagonalizes
the stress-energy tensor.Comment: 10 pages. arXiv admin note: substantial text overlap with
arXiv:1306.2174, arXiv:1306.0602, arXiv:1306.5784, arXiv:1306.400
Integrability of dual coactions on Fell bundle C*-algebras
We study integrability for coactions of locally compact groups. For abelian
groups, this corresponds to integrability of the associated action of the
Pontrjagin dual group. The theory of integrable group actions has been
previously studied by Ruy Exel, Ralf Meyer and Marc Rieffel. Our goal is to
study the close relationship between integrable group coactions and Fell
bundles. As a main result, we prove that dual coactions on C*-algebras of Fell
bundles are integrable, generalizing results by Ruy Exel for abelian groups.Comment: 24 page
Tetrads in Yang-Mills geometrodynamics
A new set of tetrads is introduced within the framework of SU(2) X U(1)
Yang-Mills field theories in four dimensional Lorentz curved spacetimes. Each
one of these tetrads diagonalizes separately and explicitly each term of the
Yang-Mills stress-energy tensor. Therefore, three pairs of planes also known as
blades, can be defined, and make up the underlying geometrical structure, at
each point. These tetrad vectors are gauge dependent on one hand, and also in
their definition, there is an additional inherent freedom in the choice of two
vector fields. In order to get rid of the gauge dependence, another set of
tetrads is defined, such that the only choice we have to make is for the two
vector fields. A particular choice is made for these two vector fields such
that they are gauge dependent, but the transformation properties of these
tetrads are analogous to those already known for curved spacetimes where only
electromagnetic fields are present. This analogy allows to establish group
isomorphisms between the local gauge group SU(2), and the tensor product of the
groups of local Lorentz tetrad transformations, either on blade one or blade
two. These theorems show explicitly that the local internal groups of
transformations are isomorphic to local spacetime groups of transformations. As
an example of application of these new tetrads, we exhibit three new gauge
invariant objects, and using these objects we show how to diagonalize the
Yang-Mills stress-energy tensor in a gauge invariant way.Comment: This new version has a new abstract and the introduction has been
modified. There is also a new section, applications. This new section has two
subsections: Gauge invariants and Diagonalization of the stress-energy
tensor. The conclusion section has also been substantially modified. There is
a new appendi
Generalized fixed point algebras for coactions of locally compact quantum groups
We extend the construction of generalized fixed point algebras to the setting
of locally compact quantum groups - in the sense of Kustermans and Vaes -
following the treatment of Marc Rieffel, Ruy Exel and Ralf Meyer in the group
case. We mainly follow Meyer's approach analyzing the constructions in the
realm of equivariant Hilbert modules.
We generalize the notion of continuous square-integrability, which is exactly
what one needs in order to define generalized fixed point algebras. As in the
group case, we prove that there is a correspondence between continuously
square-integrable Hilbert modules over an equivariant C*-algebra B and Hilbert
modules over the reduced crossed product of B by the underlying quantum group.
The generalized fixed point algebra always appears as the algebra of compact
operators of the associated Hilbert module over the reduced crossed product.Comment: 40 pages; article based on author's doctoral dissertation. Final
version to appear in M\"unster Journal of Mathematic
Euler observers in geometrodynamics
Euler observers are a fundamental tool for the study of spacetime evolution.
Cauchy surfaces are evolved through the use of hypersurface orthogonal fields
and their relationship to coordinate observers, that enable the use of already
developed algorithms. In geometrodynamics new tetrad vectors have been
introduced with outstanding simplifying properties. We are going to use these
already introduced tetrad vectors in the case where we consider a curved four
dimensional Lorentzian spacetime with the presence of electromagnetic fields.
These Einstein-Maxwell geometries will provide the new tetrad that we are going
to use in order to develop an algorithm to produce Cauchy evolution with
additional simplifying properties.Comment: 11 pages. arXiv admin note: substantial text overlap with
arXiv:1306.0602, arXiv:1306.217
Weakly proper group actions, Mansfield's imprimitivity and twisted Landstad duality
Using the theory of weakly proper actions of locally compact groups recently
developed by the authors, we give a unified proof of both reduced and maximal
versions of Mansfield's Imprimitivity Theorem and obtain a general version of
Landstad's Duality Theorem for twisted group coactions. As one application, we
obtain the stabilization trick for arbitrary twisted coactions, showing that
every twisted coaction is Morita equivalent to an inflated coaction.Comment: 29 pages. Revised version, to appear in Trans. Amer. Math. So
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