scholarly journals Is the local Lorentz invariance of general relativity implemented by gauge bosons that have their own Yang-Mills-like action?

2020 ◽  
Vol 102 (6) ◽  
Author(s):  
Kevin Cahill
2012 ◽  
Vol 21 (09) ◽  
pp. 1250072 ◽  
Author(s):  
SERGIU I. VACARU

We study the geometric and physical foundations of Finsler gravity theories with metric compatible connections defined on tangent bundles, or (pseudo) Riemannian manifolds, endowed with nonholonomic frame structure. Several generalizations and alternatives to Einstein gravity are considered, including modifications with broken local Lorentz invariance. It is also shown how such theories (and general relativity) can be equivalently re-formulated in Finsler like variables. We focus on prospects in modern cosmology and Finsler acceleration of Universe. Einstein–Finsler gravity theories are elaborated following almost the same principles as in the general relativity theory but extended to Finsler metrics and connections. Finally, some examples of generic off-diagonal metrics and generalized connections, defining anisotropic cosmological Einstein–Finsler spaces are analyzed; certain criteria for the Finsler accelerating evolution are formulated.


2009 ◽  
Vol 24 (18n19) ◽  
pp. 3327-3341 ◽  
Author(s):  
Y. M. CHO

We present an Abelian decomposition of Einstein's general relativity, viewing Einstein's theory as a gauge theory of Lorentz group and identifying the gravitational connection as the gauge potential of Lorentz group. The decomposition confirms the existence of the restricted gravity which is much simpler than Einstein's theory but which has the full local Lorentz invariance (and thus the full general invariance). Moreover, it tells that Einstein's theory can be viewed as the restricted gravity which has the Lorentz covariant valence connection as the gravitational source. With the Abelian decomposition we show how to construct all possible vacuum gravitational connections, which can be classified by the knot topology π3(S3) = π3(S2). We discuss the physical implications of our result in quantum gravity.


2005 ◽  
Vol 14 (12) ◽  
pp. 2341-2346 ◽  
Author(s):  
V. ALAN KOSTELECKÝ ◽  
ROBERTUS POTTING

In general relativity, gravitational waves propagate at the speed of light, and so gravitons are massless. The masslessness can be traced to symmetry under diffeomorphisms. However, another elegant possibility exists: masslessness can instead arise from spontaneous violation of local Lorentz invariance. We construct the corresponding theory of gravity. It reproduces the Einstein–Hilbert action of general relativity at low energies and temperatures. Detectable signals occur for sensitive experiments, and potentially profound implications emerge for our theoretical understanding of gravity.


Author(s):  
Laurent Baulieu ◽  
John Iliopoulos ◽  
Roland Sénéor

A geometrical derivation of Abelian and non- Abelian gauge theories. The Faddeev–Popov quantisation. BRST invariance and ghost fields. General discussion of BRST symmetry. Application to Yang–Mills theories and general relativity. A brief history of gauge theories.


2018 ◽  
Vol 15 (supp01) ◽  
pp. 1850139 ◽  
Author(s):  
Yen Chin Ong

Torsion-based modified theories of gravity, such as [Formula: see text] gravity, are arguably one of the very few “true” modified gravities based on well-defined geometric structures. However, the original formulation explicitly works in a specific choice of frame, which has led to considerable amount of confusion in the literature about these theories breaking local Lorentz invariance. Pathological properties such as superluminal propagation and the lack of well-posedness of Cauchy problem were found to plague [Formula: see text] gravity. Recent effort to “covariantize” [Formula: see text] gravity has, however, renewed interests in this subject. In this proceeding paper, we review and discuss issues concerning the actual number of degrees of freedom in [Formula: see text] gravity, and how this might relate to the aforementioned pathologies.


2009 ◽  
Vol 24 (08n09) ◽  
pp. 1678-1685 ◽  
Author(s):  
REZA TAVAKOL

A central assumption in general relativity is that the underlying geometry of spacetime is pseudo-Riemannian. Given the recent attempts at generalizations of general relativity, motivated both by theoretical and observational considerations, an important question is whether the spacetime geometry can also be made more general and yet still remain compatible with observations? Here I briefly summarize some earlier results which demonstrate that there are special classes of Finsler geometry, which is a natural metrical generalization of the Riemannian geometry, that are strictly compatible with the observations regarding the motion of idealised test particles and light rays. I also briefly summarize some recent attempts at employing Finsler geometries motivated by more recent developments such as those in String theory, whereby Lorentz invariance is partially broken.


Author(s):  
Jay R. Yablon

The rank-3 antisymmetric tensors which are the magnetic monopoles of SU(N) Yang-Mills gauge theory dynamics, unlike their counterparts in Maxwell’s U(1) electrodynamics, are non-vanishing, and do permit a net flux of Yang-Mills analogs to the magnetic field through closed spatial surfaces. When electric source currents of the same Yang-Mills dynamics are inverted and their fermions inserted into these Yang-Mills monopoles to create a system, this system in its unperturbed state contains exactly 3 fermions due to the monopole rank-3 and its 3 additive field strength gradient terms in covariant form. So to ensure that every fermion in this system occupies an exclusive quantum state, the Exclusion Principle is used to place each of the 3 fermions into the fundamental representation of the simple gauge group with an SU(3) symmetry. After the symmetry of the monopole is broken to make this system indivisible, the gauge bosons inside the monopole become massless, the SU(3) color symmetry of the fermions becomes exact, and a propagator is established for each fermion. The monopoles then have the same antisymmetric color singlet wavefunction as a baryon, and the field quanta of the magnetic fields fluxing through the monopole surface have the same symmetric color singlet wavefunction as a meson. Consequently, we are able to identify these fermions with colored quarks, the gauge bosons with gluons, the magnetic monopoles with baryons, and the fluxing entities with mesons, while establishing that the quarks and gluons remain confined and identifying the symmetry breaking with hadronization. Analytic tools developed along the way are then used to fill the Yang-Mills mass gap.


1991 ◽  
Vol 46 (9) ◽  
pp. 746-758 ◽  
Author(s):  
F. Winterberg

AbstractIt is hypothesized that the collapse of the wave function is a real physical phenomenon caused by vacuum fluctuations near the Planck scale. The hypothesis is suggested by a recently proposed model (Planck aether model) according to which the fundamental kinematic symmetry is the Galilei-group with the Lorentz invariance as a derived dynamic symmetry. The proposed model has the goal to derive all fields and their interactions from an exactly nonrelativistic operator field equation, resembling Heisenberg's relativistic spinor field equation. In this model the groundstate of the vacuum is a superfluid consisting of an equal number of positive and negative Planck masses interacting via delta function potentials and making the cosmological constant equal to zero. Gauge bosons come from transverse waves propagating in a lattice of quantized vortices, and spinors are explained in this model as exciton-like quasiparticles held together by gauge bosons. Because vector gauge bosons move in the model with the velocity of light, objects held together by the forcc fields of these bosons obey Lorentz invariance as a dynamic symmetry. With the longitudinal wave modes moving with a superluminal phase velocity at energies near the Planck scale, it is conjectured that the quantum mechanical wave function is real and that its collapse results from the entrapment of the wave function by these longitudinal superluminal wave modes. Because these modes occur near the Planck scale their very large zero point fluctuations might therefore trigger the collapse even through dense matter. But because the fluctuations are finite, and because the wave modes have a finite albeit very large phase velocity, the quantum mechanical correlations would be broken above a ccrtain finite length. In the limit of a vanishing Planck length, and hence vanishing gravitational constant G, the phase velocity would become infinite, and the same would be true for the length above which the correlations are broken. One therefore may say that in the limit G = 0 the collapse is infinitely fast and that in this limit the correlations are not broken even over arbitrarily large distances


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