scholarly journals Nilpotent symmetries as a mechanism for Grand Unification

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Lars Andersson ◽  
András László ◽  
Błażej Ruba
Keyword(s):  
Gauge Field ◽  
Scalar Product ◽  
Local Symmetry ◽  
Matter Field ◽  
Gauge Fields ◽  
Spacetime Symmetries ◽  
Invariant Scalar ◽  
Spacetime Manifold ◽  
Local Symmetries ◽  
Dilatation Group

Abstract In the classic Coleman-Mandula no-go theorem which prohibits the unification of internal and spacetime symmetries, the assumption of the existence of a positive definite invariant scalar product on the Lie algebra of the internal group is essential. If one instead allows the scalar product to be positive semi-definite, this opens new possibilities for unification of gauge and spacetime symmetries. It follows from theorems on the structure of Lie algebras, that in the case of unified symmetries, the degenerate directions of the positive semi-definite invariant scalar product have to correspond to local symmetries with nilpotent generators. In this paper we construct a workable minimal toy model making use of this mechanism: it admits unified local symmetries having a compact (U(1)) component, a Lorentz (SL(2, ℂ)) component, and a nilpotent component gluing these together. The construction is such that the full unified symmetry group acts locally and faithfully on the matter field sector, whereas the gauge fields which would correspond to the nilpotent generators can be transformed out from the theory, leaving gauge fields only with compact charges. It is shown that already the ordinary Dirac equation admits an extremely simple prototype example for the above gauge field elimination mechanism: it has a local symmetry with corresponding eliminable gauge field, related to the dilatation group. The outlined symmetry unification mechanism can be used to by-pass the Coleman-Mandula and related no-go theorems in a way that is fundamentally different from supersymmetry. In particular, the mechanism avoids invocation of super-coordinates or extra dimensions for the underlying spacetime manifold.

scholarly journals On Galilean Invariant and Energy Preserving BBM-Type Equations

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 878
Author(s):  
Alexei Cheviakov ◽  
Denys Dutykh ◽  
Aidar Assylbekuly
Keyword(s):  
Wave Equation ◽  
Conservation Laws ◽  
Numerical Simulations ◽  
Solitary Waves ◽  
Local Symmetry ◽  
Symmetry And Conservation Laws ◽  
Higher Order ◽  
Special Equation ◽  
Long Wave ◽  
Local Symmetries

We investigate a family of higher-order Benjamin–Bona–Mahony-type equations, which appeared in the course of study towards finding a Galilei-invariant, energy-preserving long wave equation. We perform local symmetry and conservation laws classification for this family of Partial Differential Equations (PDEs). The analysis reveals that this family includes a special equation which admits additional, higher-order local symmetries and conservation laws. We compute its solitary waves and simulate their collisions. The numerical simulations show that their collision is elastic, which is an indication of its S−integrability. This particular PDE turns out to be a rescaled version of the celebrated Camassa–Holm equation, which confirms its integrability.

scholarly journals ELEMENTARY PARTICLES AND SPIN REPRESENTATIONS

2004 ◽  
Vol 19 (05) ◽  
pp. 357-362 ◽  
Author(s):  
PAOLO MARANER
Keyword(s):  
Matter Field ◽  
Elementary Particles ◽  
Spacetime Symmetries ◽  
Spin Representation ◽  
Dimensional Spacetime ◽  
Higher Dimensional ◽  
Spin Representations ◽  
Theoretical Considerations ◽  
Unified Description

We emphasize that the group-theoretical considerations leading to SO (10) unification of electroweak and strong matter field components naturally extend to spacetime components, providing a truly unified description of all generation degrees of freedoms in terms of a single chiral spin representation of one of the groups SO (13,1), SO (9,5), SO (7,7) or SO (3,11). The realization of these groups as higher-dimensional spacetime symmetries produces unification of all fundamental fermions is a single spacetime spinor.

scholarly journals Vertex Corrections in Gauge Theories for Two-dimensional Condensed Matter Systems

1998 ◽  
Vol 12 (16n17) ◽  
pp. 1673-1692 ◽  
Author(s):  
Peter Kopietz
Keyword(s):  
Gauge Field ◽  
Condensed Matter ◽  
Finite Energy ◽  
Energy Scale ◽  
Gauge Fields ◽  
Logarithmic Correction ◽  
Two Dimensional ◽  
Numerical Constant ◽  
Self Energy ◽  
Vertex Corrections

We calculate the self-energy of two-dimensional fermions that are coupled to transverse gauge fields, taking two-loop corrections into account. Given a bare gauge field propagator that diverges for small momentum transfers q as 1/qη, 1<η≤ 2, the fermionic self-energy without vertex corrections vanishes for small frequencies ω as Σ(ω)∝ ωγ with γ=2/(1+η)<1. We show that inclusion of the leading radiative correction to the fermion-gauge field vertex leads to Σ(ω)∝ωγ [1-aη ln (ω0/ω)], where aη is a positive numerical constant and ω0 is some finite energy scale. The negative logarithmic correction is consistent with the scenario that higher order vertex corrections push the exponent γ to larger values.

Gauge fields, hidden local symmetries, and meson exchange currents

1997 ◽  
Vol 624 (4) ◽  
pp. 655-686 ◽  
Author(s):  
J. Smejkal ◽  
E. Truhlík ◽  
H. Göller
Keyword(s):  
Meson Exchange ◽  
Gauge Fields ◽  
Local Symmetries ◽  
Meson Exchange Currents

scholarly journals Synthesis and observation of non-Abelian gauge fields in real space

Science ◽  
2019 ◽  
Vol 365 (6457) ◽  
pp. 1021-1025 ◽  
Author(s):  
Yi Yang ◽  
Chao Peng ◽  
Di Zhu ◽  
Hrvoje Buljan ◽  
John D. Joannopoulos ◽  
...  
Keyword(s):  
Gauge Field ◽  
Building Blocks ◽  
Real Space ◽  
Gauge Fields ◽  
Final States ◽  
Abelian Gauge ◽  
Classical Waves ◽  
Break Time ◽  
Bohm Effect ◽  
Aharonov Bohm

Particles placed inside an Abelian (commutative) gauge field can acquire different phases when traveling along the same path in opposite directions, as is evident from the Aharonov-Bohm effect. Such behaviors can get significantly enriched for a non-Abelian gauge field, where even the ordering of different paths cannot be switched. So far, real-space realizations of gauge fields have been limited to Abelian ones. We report an experimental synthesis of non-Abelian gauge fields in real space and the observation of the non-Abelian Aharonov-Bohm effect with classical waves and classical fluxes. On the basis of optical mode degeneracy, we break time-reversal symmetry in different manners, via temporal modulation and the Faraday effect, to synthesize tunable non-Abelian gauge fields. The Sagnac interference of two final states, obtained by reversely ordered path integrals, demonstrates the noncommutativity of the gauge fields. Our work introduces real-space building blocks for non-Abelian gauge fields, relevant for classical and quantum exotic topological phenomena.

Densities of states in particles and crystals: characterization of bulk and surface properties

1986 ◽  
Vol 318 (1541) ◽  
pp. 127-134
Keyword(s):  
Electronic Structure ◽  
Surface Properties ◽  
Wave Vector ◽  
Local Symmetry ◽  
Vector Group ◽  
Densities Of States ◽  
Local Symmetries ◽  
Group Symmetries

This paper is concerned with the restrictions that local symmetry requirements impose on the structures of model clusters chosen for the reproduction of electronic structure, as densities of states, in metals. Simple techniques for the identification of such local symmetries from wave vector group symmetries are outlined. The theory is applied to iridium and comparisons are made between the calculated and measured dialectric function related to the reflectivity of the metal.

THE QUANTUM MECHANICS OF AN N=1 SUPERPARTICLE IN AN EXTENDED SUPERSPACE

1990 ◽  
Vol 05 (18) ◽  
pp. 1399-1409 ◽  
Author(s):  
MICHAEL B. GREEN ◽  
CHRISTOPHER M. HULL
Keyword(s):  
Quantum Mechanics ◽  
Finite Number ◽  
Gauge Fields ◽  
Yang Mills ◽  
Brst Cohomology ◽  
Covariant Gauge ◽  
Light Cone Quantization ◽  
Local Symmetries ◽  
Invariant Quantum ◽  
Extended Superspace

A new ten-dimensional superparticle action with local symmetries implemented via gauge fields is formulated in a superspace with an extra anticommuting space-time spinor coordinate. Light-cone quantization gives the spectrum of N=1 super-Yang-Mills. Covariant gauge choices in which the gauge fields are set to constants lead to free BRST-invariant quantum actions. Possible ghost systems include one with only a finite number of ghosts and several with an infinite number. In each case, the BRST cohomology class of zero ghost number gives the spectrum of N=1 super-Yang-Mills.

scholarly journals FERMION DYNAMICS BY INTERNAL AND SPACETIME SYMMETRIES

2009 ◽  
Vol 24 (06) ◽  
pp. 415-427 ◽  
Author(s):  
NAKIA CARLEVARO ◽  
ORCHIDEA MARIA LECIAN ◽  
GIOVANNI MONTANI
Keyword(s):  
Gauge Theory ◽  
Stationary Solutions ◽  
Gauge Fields ◽  
Spacetime Symmetries ◽  
Lorentz Transformations ◽  
Relativistic Limit ◽  
Spinor Structure ◽  
Flat Spacetime ◽  
Fermion Fields

This paper is devoted to introduce a gauge theory of the Lorentz group based on the ambiguity emerging in dealing with isometric diffeomorphism-induced Lorentz transformations. The behaviors under local transformations of fermion fields and spin connections (assumed to be ordinary world vectors) are analyzed in flat spacetime and the role of the torsion field, within the generalization to curved spacetime, is briefly discussed. The fermion dynamics is then analyzed including the new gauge fields and assuming time-gauge. Stationary solutions of the problem are also analyzed in the non-relativistic limit, to study the spinor structure of an hydrogen-like atom.

U(2) GAUGE THEORY ON NONCOMMUTATIVE GEOMETRY

2009 ◽  
Vol 24 (15) ◽  
pp. 2889-2897
Author(s):  
G. ZET
Keyword(s):  
Gauge Theory ◽  
Equations Of Motion ◽  
Local Symmetry ◽  
Noncommutative Space ◽  
Gauge Fields ◽  
Zeroth Order ◽  
Field Equations ◽  
Relativistic Analog ◽  
Analog Form ◽  
General Relativistic

We develop a model of gauge theory with U (2) as local symmetry group over a noncommutative space-time. The integral of the action is written considering a gauge field coupled with a Higgs multiplet. The gauge fields are calculated up to the second order in the noncommutativity parameter using the equations of motion and Seiberg-Witten map. The solutions are determined order by order supposing that in zeroth-order they have a general relativistic analog form. The Wu-Yang ansatz for the gauge fields is used to solve the field equations. Some comments on the quantization of the electrical and magnetical charges are also given, with a comparison between commutative and noncommutative cases.

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