Goldstone Model Research Articles

Gegenbauer’s Twin

In Twin Higgs models the dominant source of fine-tuning is the cancellation of order v2/f2 required to obtain a Standard Model-like Higgs, where v and f are the electroweak and new physics scales, respectively. Recently proposed Gegenbauer Goldstone models naturally realise v2/f2 « 1 and hence remove this source of fine-tuning. By combining the two into ‘Gegenbauer’s Twin’, we obtain a symmetry-based model for Higgs-sector naturalness consistent with current collider measurements without fine-tuning of parameters. Single-Higgs coupling deviations of a few percent and trilinear self-coupling deviations of order one are irreducible in the natural parameter space. Thus, notably, the fingerprints of Gegenbauer’s Twin could emerge first through di-Higgs measurements at the High-Luminosity LHC.

Zn modified XY and Goldstone models and vortex confinement transition

The modified XY model is a modification of the XY model by addition of a half-periodic term. The modified Goldstone model is a regular and continuum version of the modified XY model. The former admits a vortex molecule, that is, two half-quantized vortices connected by a domain wall, as a regular topological soliton solution to the equation of motion while the latter admits it as a singular configuration. Here we define the ${\mathbb Z}_n$ modified XY and Goldstone models as the $n=2$ case to be the modified XY and Goldstone models, respectively. We exhaust all stable and metastalble vortex solutions for $n=2,3$ and find a vortex confinement transition from an integer vortex to a vortex molecule of $n$ $1/n$-quantized vortices, depending on the ratio between the term of the XY model and the modified term. We find for the case of $n=3$, a rod-shaped molecule is the most stable while a Y-shaped molecule is metastable. We also construct some solutions for the case of $n=4$.The vortex confinement transition can be understood in terms of the ${\mathbb C}/{\mathbb Z}_n$ orbifold geometry.

Vortex confinement transitions in the modified Goldstone model

This paper suggests a new theoretical model, in which topological objects such as vortices, half-vortices, and solitons coexist. They strongly interact and form topological molecules, triggering a confiment/deconfinement topological phase transition. Its findings provide applications to Josephson-junction arrays of superconducting and nematic liquid crystal films

On Goldstone Fields with Spin Higher than 1/2

We review the properties of 3d non-linear models of vector and vector-spinor Goldstone fields associated with the spontaneous breaking of certain higher-spin counterparts of supersymmetry (so-called Hietarinta algebras), whose Lagrangians are of the Volkov–Akulov type. At the quadratic order, these Lagrangians contain, respectively, the Chern–Simons and Rarita–Schwinger terms. The vector Goldstone model has a propagating degree of freedom which, in a decoupling limit, is a quartic Galileon scalar field (similar to those appearing in models of modified gravity). On the other hand, the vector-spinor goldstino retains the gauge symmetry of the Rarita–Schwinger action and eventually reduces to the latter by a non-linear field redefinition. We thus find that, in three space-time dimensions, the free Rarita–Schwinger action is invariant under a hidden rigid symmetry generated by fermionic vector-spinor operators and acting non-linearly on the Rarita–Schwinger goldstino.

Can Chern-Simons or Rarita-Schwinger be a Volkov-Akulov Goldstone?

We study three-dimensional non-linear models of vector and vector-spinor Goldstone fields associated with the spontaneous breaking of certain higher-spin counterparts of supersymmetry whose Lagrangians are of a Volkov-Akulov type. Goldstone fields in these models transform non-linearly under the spontaneously broken rigid symmetries. We find that the leading term in the action of the vector Goldstone model is the Abelian Chern-Simons action whose gauge symmetry is broken by a quartic term. As a result, the model has a propagating degree of freedom which, in a decoupling limit, is a quartic Galileon scalar field. The vector-spinor goldstino model turns out to be a non-linear generalization of the three-dimensional Rarita-Schwinger action. In contrast to the vector Goldstone case, this non-linear model retains the gauge symmetry of the Rarita-Schwinger action and eventually reduces to the latter by a non-linear field redefinition. We thus find that the free Rarita-Schwinger action is invariant under a hidden rigid super-symmetry generated by fermionic vector-spinor operators and acting non-linearly on the Rarita-Schwinger goldstino.

Goldstone models of modified gravity

We investigate scalar-tensor theories where matter couples to the scalar field via a kinetically dependent conformal coupling. These models can be seen as the low-energy description of invariant field theories under a global Abelian symmetry. The scalar field is then identified with the Goldstone mode of the broken symmetry. It turns out that the properties of these models are very similar to the ones of ultralocal theories where the scalar-field value is directly determined by the local matter density. This leads to a complete screening of the fifth force in the Solar System and between compact objects, through the ultralocal screening mechanism. On the other hand, the fifth force can have large effects in extended structures with large-scale density gradients, such as galactic halos. Interestingly, it can either amplify or damp Newtonian gravity, depending on the model parameters. We also study the background cosmology and the linear cosmological perturbations. The background cosmology is hardly different from its $\Lambda$-CDM counterpart whilst cosmological perturbations crucially depend on whether the coupling function is convex or concave. For concave functions, growth is hindered by the repulsiveness of the fifth force whilst it is enhanced in the convex case. In both cases, the departures from the $\Lambda$-CDM cosmology increase on smaller scales and peak for galactic structures. For concave functions, the formation of structure is largely altered below some characteristic mass, as smaller structures are delayed and would form later through fragmentation, as in some warm dark matter scenarios. For convex models, small structures form more easily than in the $\Lambda$-CDM scenario.

Extended Higgs sectors in the context of supersymmetry at the LHC

We studied the extension of Standard Model (SM) Higgs sector with $SU(2)$ triplet and SM gauge singlet in the context of supersymmetry. For a $Z_3$ symmetric superpotential where the singlet field generates the bi-linear Higgs mixing term between two Higgs doublets dynamically. Models like this often have a very light pseudoscalar as pseudo-Nambu Goldstone model of an extra $U(1)$ symmetry. We investigate the possibility of such light hidden Higgs boson with the data of the discovered Higgs boson around 125 GeV. Along with the neutral sector, the charged Higgs bosons in the triplet extended case are really interesting as the triplet charged Higgs bosons give rise to new decay mode to $Z W^\pm$ along with $ a_1 W^\pm$ due to the existence of light pseudoscalar. These new modes can be looked for at the LHC in the search for the Higgs bosons in other representations of $SU(2)$.

Natural inflation: consistency with cosmic microwave background observations of Planck and BICEP2

Natural inflation is a good fit to all cosmic microwave background (CMB) data and may be the correct description of an early inflationary expansion of the Universe. The large angular scale CMB polarization experiment BICEP2 has announced a major discovery, which can be explained as the gravitational wave signature of inflation, at a level that matches predictions by natural inflation models. The natural inflation (NI) potential is theoretically exceptionally well motivated in that it is naturally flat due to shift symmetries, and in the simplest version takes the form V(ϕ) = Λ4 [1 ± cos(Nϕ/f)]. A tensor-to-scalar ratio r > 0.1 as seen by BICEP2 requires the height of any inflationary potential to be comparable to the scale of grand unification and the width to be comparable to the Planck scale. The Cosine Natural Inflation model agrees with all cosmic microwave background measurements as long as f ⩾ mPl (where mPl = 1.22 × 1019 GeV) and Λ ∼ mGUT ∼ 1016 GeV. This paper also discusses other variants of the natural inflation scenario: we show that axion monodromy with potential V∝ ϕ2/3 is inconsistent with the BICEP2 limits at the 95% confidence level, and low-scale inflation is strongly ruled out. Linear potentials V ∝ ϕ are inconsistent with the BICEP2 limit at the 95% confidence level, but are marginally consistent with a joint Planck/BICEP2 limit at 95%. We discuss the pseudo-Nambu Goldstone model proposed by Kinney and Mahanthappa as a concrete realization of low-scale inflation. While the low-scale limit of the model is inconsistent with the data, the large-field limit of the model is marginally consistent with BICEP2. All of the models considered predict negligible running of the scalar spectral index, and would be ruled out by a detection of running.

Emergent Gravity, Violated Relativity and Dark Matter

The nonlinear affine Goldstone model of the emergent gravity, built on the nonlinearly realized/ hidden affine symmetry, is concisely revisited. Beyond General Relativity, the explicit violation of general invariance/relativity, under preserving general covariance, is exposed. Dependent on a nondynamical affine connection, a generally covariant second-order effective Lagrangian for metric gravity is worked out, with the general relativity violation and the gravitational dark matter serving as the signatures of emergence.

Scalar hairy black holes and solitons in a gravitating Goldstone model

We study black hole solutions of Einstein gravity coupled to a specific global symmetry breaking Goldstone model described by an O(3) isovector scalar field in four spacetime dimensions. Our configurations are static and spherically symmetric, approaching at infinity a Minkowski spacetime background. A set of globally regular, particle-like solutions are found in the limit of vanishing event horizon radius. These configurations can be viewed as ‘regularised’ global monopoles, since their mass is finite and the spacetime geometry has no deficit angle. As an unusual feature, we notice the existence of extremal black holes in this model defined in terms of gravity and scalar fields only.

Spontaneous symmetry breaking for long-wave gravitons in the early Universe

It is shown that nonlinear terms in the equations for gravitons in the background of curved space-time of the expanding Universe can solve the problem of the negative effective mass squared, formally arising in the linear approximation for gravitons. Similarly to the well-known spontaneous symmetry breaking in the Goldstone model, one must take another vacuum, so that a nonzero vacuum expectation value of the quantized graviton field leads to a change in the graviton spectrum. There appear two graviton fields, one with positive mass, another with zero mass. The energy density and the density of particles created by gravitation of the expanding Universe are calculated for some special cases of the scale factor. Numerical results are obtained for the case of a dust universe.

THE EFFECTIVE ACTION AND EQUATIONS OF MOTION OF CURVED LOCAL AND GLOBAL VORTICES: ROLE OF THE FIELD EXCITATIONS

The effective actions for both local and global curved vortices are derived based on the derivative expansion of the corresponding field theoretic actions of the nonrelativistic Abelian Higgs and Goldstone models. The role of excitations of the modulus and the phase of the scalar field and of the gauge field (the Bogolyubov-Anderson mode) emitted and reabsorbed by vortices is elucidated. In the case of the local (gauge) magnetic vortex, they are necessary for cancellation of the long distance divergence when using the transverse form of the electric gauge field strength of the background field. In the case of global vortex taking them into account results in the Greiter–Wilczek–Witten form of the effective action for the Goldstone mode. The expressions for transverse Magnus-like force and the vortex effective mass for both local and global vortices are found. The equations of motion of both type of vortices including the terms due to the field excitations are obtained and solved in cases of large and small contour displacements.

Goldstone models in D + 1 dimensions, D = 3, 4, 5, supporting stable and zero topological charge solutions

We study finite energy static solutions to a global symmetry breaking Goldstone model described by an isovector scalar field in D + 1 spacetime dimensions. Both topologically stable multisolitons with arbitrary winding numbers and zero topological charge soliton–antisoliton solutions are constructed numerically in D = 3, 4, 5. We have explored the types of symmetries the systems should be subjected to, for there to exist multisoliton and soliton–antisoliton pairs in D = 3, 4, 5, 6. These findings are underpinned by constructing numerical solutions in the D ⩽ 5 examples. Subject to axial symmetry, only multisolitons of all topological charges exist in even D, and in odd D only zero and unit topological charge solutions exist. Subjecting the system to weaker than axial symmetries results in the existence of all the possibilities in all dimensions. Our findings also apply to finite ‘energy’ solutions to Yang–Mills and Yang–Mills–Higgs systems as well as to sigma models, but we find the numerical work for the Goldstone models more accessible.

Antiperiodic solitons of the Goldstone model on S1

Our purpose is to present all static solutions of the Goldstone model on a circle in 1+1 dimensions with an antiperiodicity condition imposed on the scalar fields. Jacobi elliptic and standard trigonometric functions are used to express the solutions found and stability analysis of the latter is what follows. Classically stable quasi-topological solitons are identified.

Localisation of Fermions to brane: Codimensiond 2

We investigate $4+d$ dimensional fermionic models in which the system in codimension-$d$ supports a topologically stable solution, and in which the fermion may be localised to the brane, with power law in 'instanton' backgrounds and exponentially in 'soliton' backgrounds. When the fermions are isoscalars, the mechanism fails, while for isospinor fermions it is successful. As backgrounds we consider instantons of Yang--Mills and sigma models in even codimensions, solitons of sigma models in odd codimensions, as well as solitons of Higgs and Goldstone models in all codimensions.

The Goldstone model static solutions on S1

We study in a systematic way all static solutions of the Goldstone model in 1 + 1 dimensions with a periodicity condition imposed on the spatial coordinate. The solutions are presented in terms of standard trigonometric functions and of Jacobi elliptic functions. Their stability analysis is carried out, and the complete list of classically stable quasi-topological solitons is given. AMS classification scheme number: 12B90

Does Jack Goldstone's Model of Early Modern State Crises Apply to Russia?

In 1991 Jack A. Goldstone published an important book, Revolution and Rebellion in the Early Modern World, in which he boldly charted a new way to explain the basic causes of revolution throughout Eurasia from the sixteenth to the nineteenth centuries. Goldstone attempts to explain the periodic waves of early modern state crises, rebellions, and civil wars in widely divergent cultures and geographic settings by developing an intriguing model of state breakdowns which he applies primarily to England, France, the Ottoman Empire, and China. Goldstone views the crises of large agrarian absolute monarchies mainly as the result of a single basic process: prolonged population growth in the context of relatively inflexible economic and social structures, eventually resulting in rapid price inflation, sudden shifts in resources, and rising social demands on a scale that most agrarian-based bureaucratic states found overwhelming. Simply put, long-term population and price in-creases have helped push rigid political, economic, and social institutions into crisis. Since the publication of Goldstone's work, there has been a positive response to it from many historians and social scientists. So far, however, no one has attempted to test Goldstone's model by applying it to a state break-down which the author did not include in his study. In my own research I have discovered that Goldstone's model may apply to Russia even though he did not focus on it. In this article I hope to demonstrate that his work helps explain Russia's Time of Troubles (1598–1613) and that the Russian test case helps validate Goldstone's model as an important contribution to comparative history.

European Revolutions, 1492-1992. Charles Tilly , Jacques Le GoffRevolution and Rebellion in the Early Modern World. Jack A. Goldstone

Previous articleNext article No AccessBook ReviewsEuropean Revolutions, 1492-1992. Charles Tilly , Jacques Le Goff Revolution and Rebellion in the Early Modern World. Jack A. Goldstone Daniel ChirotDaniel Chirot Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Journal of Modern History Volume 67, Number 3Sep., 1995 Article DOIhttps://doi.org/10.1086/245177 Views: 18Total views on this site Citations: 1Citations are reported from Crossref Copyright 1995 The University of ChicagoPDF download Crossref reports the following articles citing this article:Chester Dunning Does Jack Goldstone's Model of Early Modern State Crises Apply to Russia?, Comparative Studies in Society and History 39, no.33 (Apr 2012): 572–592.https://doi.org/10.1017/S0010417500020764

Revolution and Rebellion in the Early Modern World.Jack A. Goldstone

Previous articleNext article No AccessBook ReviewsRevolution and Rebellion in the Early Modern World. Jack A. Goldstone John MarkoffJohn Markoff Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by American Journal of Sociology Volume 98, Number 4Jan., 1993 Article DOIhttps://doi.org/10.1086/230096 Views: 12Total views on this site Citations: 1Citations are reported from Crossref Copyright 1993 The University of ChicagoPDF download Crossref reports the following articles citing this article:Chester Dunning Does Jack Goldstone's Model of Early Modern State Crises Apply to Russia?, Comparative Studies in Society and History 39, no.33 (Apr 2012): 572–592.https://doi.org/10.1017/S0010417500020764

Upper bounds to 1-loop symmetry restoration for the Goldstone model in R q+1 × T p in the low-mass and weak-coupling limit

We obtain critical values for the compactification lengths relevant for the restoration of spontaneously broken symmetries in the Goldstone model. We find them by varying both the space dimension and the number of compactified directions. More precisely, our approach consists in applying Epstein zeta-functions to evaluate the first corrections to the potential, and is used for untwisted and also for twisted scalar fields.