scholarly journals Gravitationally coupled magnetic monopole and conformal symmetry breakingThis paper was presented at the Theory CANADA 4 conference, held at Centre de recherches mathématiques, Montréal, Québec, Canada on 4–7 June 2008.

2009 ◽  
Vol 87 (3) ◽  
pp. 251-254 ◽  
Author(s):  
Ariel Edery ◽  
Luca Fabbri ◽  
M. B. Paranjape

We consider a Georgi–Glashow model conformally coupled to gravity. The conformally invariant action includes a triplet of scalar fields and SO(3) non-Abelian gauge fields. However, the usual mass term μ2ϕ2 is forbidden by the symmetry, and this role is now played by the conformal coupling of the Ricci scalar to the scalar fields. Spontaneous symmetry breaking occurs via gravitation. The spherically symmetric solutions correspond to localized solitons (magnetic monopoles) in asymptotically anti-de Sitter (AdS) spacetime and the metric outside the core of the monopole is found to be Schwarzschild–AdS. Though conformal symmetry excludes the Einstein–Hilbert term in the original action, it emerges in the effective action after spontaneous symmetry breaking and dominates the low-energy–long-distance regime outside the core of the monopole.

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Taeyoon Moon ◽  
Phillial Oh

We explore the possibility of the spontaneous symmetry breaking in 5D conformally invariant gravity, whose action consists of a scalar field nonminimally coupled to the curvature with its potential. Performing dimensional reduction via ADM decomposition, we find that the model allows an exact solution giving rise to the 4D Minkowski vacuum. Exploiting the conformal invariance with Gaussian warp factor, we show that it also admits a solution which implements the spontaneous breaking of conformal symmetry. We investigate its stability by performing the tensor perturbation and find the resulting system is described by the conformal quantum mechanics. Possible applications to the spontaneous symmetry breaking of time-translational symmetry along the dynamical fifth direction and the brane-world scenario are discussed.


2015 ◽  
Vol 93 (11) ◽  
pp. 1352-1355
Author(s):  
M.R. Tanhayi ◽  
S. Ejlali

In this paper, we study the conformal symmetry breaking in conformally invariant Hilbert–Einstein action via expansion of action up to second order around the background space–time. It is shown that the theory can be described a non-tachyonic and ghost-free theory that propagates massless spin-2, massive gauge, and also massless scalar fields.


2014 ◽  
Vol 29 (08) ◽  
pp. 1450047 ◽  
Author(s):  
A. Mohamadnejad ◽  
S. Deldar

Applying Cho–Faddeev–Niemi decomposition for SU(2) Yang–Mills field, we obtain the Abelian–Higgs Lagrangian by some approximation. Abelian–Higgs Lagrangian with a spontaneous symmetry breaking potential has vortex solutions known as Nielsen–Olesen solutions. We conclude that vortices as well as magnetic monopoles can exist in Cho–Faddeev–Niemi decomposition of SU(2) Yang–Mills field.


2010 ◽  
Vol 25 (22) ◽  
pp. 4195-4220 ◽  
Author(s):  
E. I. GUENDELMAN

A general coordinate invariant theory is constructed where confinement of gauge fields and gauge dynamics in general is governed by the spontaneous symmetry breaking (s.s.b.) of scale invariance. The model uses two measures of integration in the action, the standard [Formula: see text] where g is the determinant of the metric and another measure Φ independent of the metric. To implement scale invariance, a dilaton field is introduced. Using the first-order formalism, curvature (ΦR and [Formula: see text]) terms, gauge field term ([Formula: see text] and [Formula: see text]) and dilaton kinetic terms are introduced in a conformally invariant way. Exponential potentials for the dilaton break down (softly) the conformal invariance down to global scale invariance, which also suffers s.s.b. after integrating the equations of motion. The model has a well-defined flat space limit. As a result of the s.s.b. of scale invariance phases with different vacuum energy density appear. Inside the bags, that is in the regions of larger vacuum energy density, the gauge dynamics is normal, that is nonconfining, while for the region of smaller vacuum energy density, the gauge field dynamics is confining. Likewise, the dynamics of scalars, like would be Goldstone bosons, is suppressed inside the bags.


2007 ◽  
Vol 16 (09) ◽  
pp. 2794-2797 ◽  
Author(s):  
HILMAR FORKEL ◽  
MICHAEL BEYER ◽  
TOBIAS FREDERICO

An approximate holographic dual of QCD is constructed and shown to reproduce the empirical linear trajectories of universal slope on which the square masses of radially and orbitally excited hadrons join. Conformal symmetry breaking and other IR effects are described exclusively by deformations of the anti-de Sitter background metric. The predictions for the light hadron spectrum include new relations between ground state masses and trajectory slopes and are in good overall agreement with experimental data.


2012 ◽  
Vol 01 (02) ◽  
pp. 50-51
Author(s):  
Peter Higgs

The story begins in 1960, when Nambu, inspired by the BCS theory of superconductivity, formulated chirally invariant relativistic models of interacting massless fermions in which spontaneous symmetry breaking generates fermionic masses (the analogue of the BCS gap). Around the same time Jeffrey Goldstone discussed spontaneous symmetry breaking in models containing elementary scalar fields (as in Ginzburg-Landau theory). I became interested in the problem of how to avoid a feature of both kinds of model, which seemed to preclude their relevance to the real world, namely the existence in the spectrum of massless spin-zero bosons (Goldstone bosons). By 1962 this feature of relativistic field theories had become the subject of the Goldstone theorem.


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