arXiv subjects

J. L. Chkareuli

Publications and source records attributed to J. L. Chkareuli.

At least 19 recordsLinked to original sources

arXiv2026

SL(2N,C) Yang-Mills Theories: Direct Internal Forces and Emerging Gravity

A four-dimensional gauge-gravity unification based on local $SL(2N,C)$ symmetry is developed in a universal Yang--Mills-type setting, which, however, appears dynamically consistent only in the symmetry-broken phase. In the exact symmetry limit the theory may only be formulated in a premetric framework, where the accompanying tetrad multiplets, though promoted to dynamical fields, do not yet satisfy the conventional invertibility conditions. An ordinary Einstein--Cartan spacetime geometry emerges only in the broken post-soldering phase, in which the $SL(2N,C)$ tetrad multiplets are treated as constrained dynamical fields selecting a neutral internal symmetry branch. This realizes the breaking $SL(2N,C)\to SL(2,C)\times SU(N)$, thereby lifting all noncompact internal directions, while the surviving neutral tetrad is, as usual, associated with the gravitational field. A special ghost-free curvature-squared Lagrangian provides a consistent quadratic sector for the spin connection, propagating only admissible connection modes: the massless $SU(N)$ vector fields together with massive axial-vector and pseudoscalar multiplets. The Einstein--Cartan linear curvature term is argued to arise radiatively from fermion loops, thereby relating the gravitational scale to the same $SL(2N,C)$-covariant matter sector that defines the unified gauge coupling. Finally, the matter sector points to a deeper elementarity of $SL(2N,C)$ spinors, identified with preon constituents whose bound states form the observed quarks and leptons. Anomaly matching between preons and composites singles out $N=8$. The chain $SL(16,C)\to SL(2,C)\times SU(8)$ then naturally yields three composite quark--lepton families, while filtering out extraneous heavy states.

hep-th↗

arXiv2025

Gravity and Unification: Insights from SL(2N,C) Gauge Theories

The perspective that gravity may govern the unification of all elementary forces calls for extending the gauge-gravity symmetry $SL(2,C)$ to the broader local symmetry $SL(2N,C)$, where $N$ reflects the internal $SU(N)$ subgroup. This extension yields a consistent hyperunification framework in which -- aside from the linear gravity Lagrangian, to which only tensor fields contribute -- the quadratic curvature sector is fully unified across all gauge submultiplets. Tetrad fields play a central role: once dynamical, their invertibility -- treated as a nonlinear sigma-model type length constraint -- naturally implies condensation and thereby triggers spontaneous breaking of $SL(2N,C)$. As a result, while the full gauge multiplet contains vector, axial-vector, and tensor submultiplets, only the vector submultiplet remains in the observed spectrum; the axial-vector and tensor submultiplets acquire large masses at the symmetry-breaking scale. The effective symmetry reduces to $SL(2,C)\times SU(N)$, collecting together $SL(2,C)$ gauge gravity and the $SU(N)$ grand-unified sector. Since states in $SL(2N,C)$ are also classified by spin magnitudes, many $SU(N)$ GUT models -- such as standard $SU(5)$% -- appear ill-suited for fundamental spin-$1/2$ quarks and leptons. By contrast, applying $SL(2N,C)$ to a composite framework with chiral preons in fundamental representations points to $SL(16,C)$, with effective $% SL(2,C)\times SU(8)$ accommodating all three quark-lepton families, as a compelling candidate for hyperunification of all fundamental forces.

hep-th↗

arXiv2024

On gravity unification in SL(2N,C) gauge theories

The local $SL(2N,C)$ symmetry is shown to provide, when appropriately constrained, a viable framework for a consistent unification of the known elementary forces, including gravity. Such a covariant constraint implies that an actual gauge field multiplet in the $SL(2N,C)$ theory is ultimately determined by the associated tetrad fields which not only specify the geometric features of spacetime but also govern which local internal symmetries are permissible within it. As a consequence, upon the covariant removal of all "redundant" gauge field components, the entire theory only exhibits the effective $SL(2,C)\times SU(N)$ symmetry, comprising $SL(2,C)$ gauge gravity on one hand and $SU(N)$ grand unified theory on the other. Given that all states involved in the $SL(2N,C)$ theories are additionally classified according to their spin values, many potential $SU(N)$ GUTs, including the conventional $SU(5)$ theory, appear to be irrelevant for standard spin $1/2$ quarks and leptons. Meanwhile, applying the $SL(2N,C)$ symmetry to the model of composite quarks and leptons with constituent chiral preons in its fundamental representations reveals, under certain natural conditions, that among all accompanying $SU(N)_{L}\times SU(N)_{R}$ chiral symmetries of preons and their composites only the $SU(8)_{L}\times SU(8)_{R}$ meets the anomaly matching condition ensuring masslessness of these composites at large distances. This, in turn, identifies $SL(16,C)$ with the effective $SL(2,C)\times SU(8)$ symmetry, accommodating all three families of composite quarks and leptons, as the most likely candidate for hyperunification of the existing elementary forces.

hep-th↗

arXiv2023

Unification of elementary forces in gauge SL(2N,C) theories

We argue that the gauge $SL(2N,C)$ theories may point to a possible way where the known elementary forces, including gravity, could be consistently unified. Remarkably, while all related gauge fields are presented in the same adjoint multiplet of the $SL(2N,C)$ symmetry group, the tensor field submultiplet providing gravity can be naturally suppressed in the weak-field approach developed for accompanying tetrad fields. As a result, the whole theory turns out to effectively possess the local $SL(2,C)\times SU(N)$ symmetry so as to naturally lead to the $SL(2,C)$ gauge gravity, on the one hand, and the $SU(N)$ grand unified theory, on the other. Since all states involved in the $SL(2N,C)$ theories are additionally classified according to their spin values, many possible $SU(N)$ GUTs - including the conventional one-family $SU(5)$ theory - appear not to be relevant for the standard $1/2$ spin quarks and leptons. Meanwhile, the $SU(8)$ grand unification for all three families of composite quarks and leptons that stems from the $SL(16,C)$ theory seems to be of special interest that is studied in some detail.

hep-th↗

arXiv2021

Gauge Fields as Constrained Composite Bosons

We reconsider a scenario in which photons and other gauge fields appear as the composite vector bosons made of the fermion pairs that may happen with or without spontaneous violation of Lorentz invariance. The class of composite models for emergent gauge fields is proposed, where these fields are required to be restricted by by the nonlinear covariant constraint of type $ A_{μ}^{2}=M^{2}$. Such a constraint may only appear if the corresponding fermion currents in the prototype model, being invariant under some global internal symmetry $G$, are properly constrained as well. In contrast to the conventional approach, the composite bosons emerged in this way appear naturally massless, the global symmetry $G$ in the model turns into the local symmetry $G_{loc}$, while the vector field constraint reveals itself as the gauge fixing condition. Finally, we consider the case when the constituent fermions generating emergent gauge bosons could be at the same time the preons composing the known quark-lepton species in the Standard Model and Grand Unified Theories.

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arXiv2020

On the lightlike Lorentz violation

We consider the lightlike spontaneous Lorentz invariance violation (SLIV) appearing through the zero "length-fixing" constraint put on a gauge vector field, $A_{μ}A^{μ}=0$, and discuss its physical consequences in the framework of a conventional QED and beyond. Again, as in the timelike and spacelike SLIV cases, $A_{μ}A^{μ}=\pm M_{A}^{2}$ ($M_{A}$ is a scale of SLIV), while this constraint leads to an emergence of the Nambu-Goldstone modes collected in physical photon, the SLIV itself is still left unobservable unless gauge invariance in the theory is broken. At the same time, a crucial difference with the two former cases is that the asymmetrical vacuum corresponding to the lightlike Lorentz violation appears infinitely degenerated with all other vacua including the symmetrical one. We show that this degeneracy can be lifted out by introducing an extra gauge vector field being sterile with respect to an ordinary matter, though having some potential couplings with the basic $A_{μ}$ field. A slight mixing of them makes the underlying gauge invariance to be partially broken due to which physical Lorentz invariance occurs broken as well. This may cause a variety of the Lorentz violating processes some of which are briefly discussed.

hep-ph↗

arXiv2019

SU(8) Grand Unification from Composite Quarks and Leptons

We consider the $L$-$R$ symmetric composite model for quarks and leptons where constituent preons possessing some local $SU(N)_{MF}$ metaflavor symmetry are bound by the chiral $SO(n)_{L}\times SO(n)_{R}$ gauge metacolor forces. The strengthening of the 't Hooft's anomaly matching condition, when the massless fermion composites are required to complete a single representation of the $SU(N)_{MF}$ rather than some set of its representations, allows to fix the number of basic metaflavors $N$. Particularly, just eight left-handed and eight right-handed preons and their composites preserving the global chiral symmetry $SU(8)_{L}\times SU(8)_{R}$ are turned out to underlie the physical world at small distances that uniquely identifies the local metaflavor symmetry $SU(8)_{MF}$ as its effective unified symmetry. We next show that the spontaneous $L$-$R$ symmetry violation caused by composite scalars reduces this initially vectorlike $SU(8)_{MF}$ theory down to the conventional $SU(5)$ GUT with an extra local family symmetry $SU(3)_{F}$ and three standard families of quarks and leptons. Though the tiny confinement scale for universal preons composing both quarks and leptons makes it impossible to directly confirm their composite nature, simultaneous emergence of several extra $SU(5)\times SU(3)_{F}$ multiplets of heavy composite fermions may help with a model verification. Generally, they may be located at scales from $O(100)$ $TeV$ up to the Planck mass scale depending on an interplay between the compositeness scale and scale of the family symmetry $SU(3)_{F}$. Some of them through a natural see-saw mechanism provide neutrino masses which, in contrast to conventional picture, appear to follow an inverted family hierarchy. Others mix with ordinary quark-lepton families in a way that there may arise a marked violation of unitarity in the CKM matrix for leptons.

hep-ph↗

arXiv2018

Emergent photons and gravitons

Now, it is already not a big surprise that due to the spontaneous Lorentz invariance violation (SLIV) there may emerge massless vector and tensor Goldstone modes identified particularly with photon and graviton. Point is, however, that this mechanism is usually considered separately for photon and graviton, though in reality they appear in fact together. In this connection, we recently develop the common emergent electrogravity model which would like to present here. This model incorporates the ordinary QED and tensor field gravity mimicking linearized general relativity. The SLIV is induced by length-fixing constraints put on the vector and tensor fields, $A_{μ}^{2}=\pm M_{A}^{2}$ and $H_{μν}^{2}=\pm M_{H}^{2}$ ($M_{A}$ and $M_{H}$ are the proposed symmetry breaking scales) which possess the much higher symmetry then the model Lagrangian itself. As a result, the twelve Goldstone modes are produced in total and they are collected into the vector and tensor field multiplets. While photon is always the true vector Goldstone boson, graviton contain pseudo-Goldstone modes as well. In terms of the appearing zero modes, theory becomes essentially nonlinear and contains many Lorentz and CPT violating interaction. However, as argued, they do not contribute in processes which might lead to the physical Lorentz violation. Nonetheless, how the emergent electrogravity theory could be observationally differed from conventional QED and GR theories is also briefly discussed.

physics.gen-ph↗

arXiv2018

Eightfold Way for Composite Quarks and Leptons

It is now almost clear that there is no meaningful internal symmetry higher than the one family GUTs like as $SU(5)$, $SO(10)$, or $E(6)$ for classification of all observed quarks and leptons. Any attempt to describe all three quark-lepton families in the GUT framework leads to higher symmetries with enormously extended representations which contain lots of exotic states as well that never been detected in an experiment. This may motivate us to continue seeking a solution in some subparticle or preon models for quark and leptons just like as in the nineteen-sixties the spectroscopy of hadrons had required to seek a solution in the quark model for hadrons. At that time, there was very popular some concept invoked by Murray Gell-Mann and called the Eightfold Way according to which all low-lying baryons and mesons are grouped into octets. We now find that this concept looks much more adequate when it is applied to elementary preons and composite quarks and leptons. Remarkably, just the eight left-handed and right-handed preons and their generic metaflavor symmetry $SU(8)$ may determine the fundamental constituens of material world. This result for an admissible number of preons, $N=8$, appears as a solution to the 't Hooft's anomaly matching condition provided that (1) this condition is satisfied separately for the $L$-preon and $R$-preon composites and (2) these composites fill only one multiplet of some $SU(N)$ symmetry group rather than a set of its multiplets. We next show that a partial $L$-$R$ symmetry breaking reduces an initially emerged vectorlike $SU(8)$ theory down to the conventional $SU(5)$ GUT with an extra local family symmetry $SU(3)_{F}$ and three standard generations of quarks and leptons.

physics.gen-ph↗

arXiv2018

Lorentzian Goldstone modes shared among photons and gravitons

It has long been known that photons and gravitons may appear as vector and tensor Goldstone modes caused \ by spontaneous Lorentz invariance violation (SLIV). Usually this approach is considered for photons and gravitons separately. We develop the emergent electrogravity theory consisting of the ordinary QED and the tensor field gravity model which mimics the linearized general relativity in Minkowski spacetime. In this theory, Lorentz symmetry appears incorporated into higher global symmetries of the length-fixing constraints put on the vector and tensor fields involved, $A_{μ}^{2}=\pm M_{A}^{2}$ and $H_{μν}^{2}=\pm M_{H}^{2}$ ($M_{A}$ and $M_{H}$ are the proposed symmetry breaking scales). We show that such a SLIV pattern being related to breaking of global symmetries underlying these constraints induces the massless Goldstone and pseudo-Goldstone modes shared among photon and graviton. While for a vector field case the symmetry of the constraint coincides with Lorentz symmetry $SO(1,3)$ of the electrogravity Lagrangian, the tensor field constraint itself possesses much higher global symmetry $SO(7,3)$, whose spontaneous violation provides a sufficient number of zero modes collected in a graviton. Accordingly, while photon may only contain true Goldstone modes, graviton appears at least partially composed from pseudo-Goldstone modes rather than from pure Goldstone ones. When expressed in terms of these modes, the theory looks essentially nonlinear and contains a variety of Lorentz and $CPT$ violating couplings. However, all SLIV effects turn out to be strictly cancelled in the lowest order processes that is considered in some detail. How this emergent electrogravity theory could be observationally differed from conventional QED and GR theories is also briefly discussed.

hep-th↗

arXiv2017

Poincaré gauge gravity: an emergent scenario

The Poincaré gauge gravity (PGG) with the underlying vector fields of tetrads and spin-connections is perhaps the best theory candidate for gravitation to be unified with the other three elementary forces of nature. There is a clear analogy between local frame in PGG and local internal symmetry space in the Standard Model. As a result, the spin-connection fields, gauging the local frame Lorentz symmetry group SO(1,3)_{LF}, appear in PGG much as photons and gluons appear in SM. We propose that such an analogy may follow from their common emergent nature allowing to derive PGG in the same way as conventional gauge theories. In essence, we start with an arbitrary theory of some vector and fermion fields which possesses only global spacetime symmetries, such as Lorentz and translational invariance, in flat Minkowski space. The two vector field multiplets involved are proposed to belong, respectively, to the adjoint (A_{μ}^{ij}) and vector (e_{μ}^{i}) representations of the starting global Lorentz symmetry. We show that if these prototype vector fields are covariantly constrained, A_{μ}^{ij}A_{ij}^{μ}=M_{A} and e_{μ}^{i}e_{i}^{μ}=M_{e}, thus causing a spontaneous violation of the accompanying global symmetries (M_{A,e} are their proposed violation scales), then the only possible theory compatible with these length-preserving constraints is turned out to be the gauge invariant PGG, while the corresponding massless (pseudo)Goldstone modes are naturally collected in the emergent gauge fields of tetrads and spin-connections. In a minimal theory case being linear in a curvature we unavoidably come to the Einstein-Cartan theory. The extending theories with propagating spin-connection and tetrad modes are also considered and their possible unification with the Standard Model is briefly discussed.

gr-qc↗

arXiv2016

Gauge Symmetries Emerging from Extra Dimensions

We argue that extra dimensions with a properly chosen compactification scheme could be a natural source for emergent gauge symmetries. Actually, some proposed vector field potential terms or polynomial vector field constraints introduced in five-dimensional Abelian and non-Abelian gauge theory is shown to smoothly lead to spontaneous violation of an underlying 5D spacetime symmetry and generate pseudo-Goldstone vector modes as conventional 4D gauge boson candidates. As a special signature, there appear, apart from conventional gauge couplings, some properly suppressed direct multi-photon (multi-boson, in general) interactions in emergent QED and Yang-Mills theories whose observation could shed light on their high-dimensional nature. Moreover, in emergent Yang-Mills theories an internal symmetry G also occurs spontaneously broken to its diagonal subgroups once 5D Lorentz violation happens. This breaking origins from the extra vector field components playing a role of some adjoint scalar field multiplet in the 4D spacetime. So, one naturally has the Higgs effect without a specially introduced scalar field multiplet. Remarkably, when being applied to Grand Unified Theories this results in a fact that the emergent GUTs generically appear broken down to the Standard Model just at the 5D Lorentz violation scale M. PACS numbers: 11.15.-q, 11.30.Cp, 11.30.Pb, 11.10.Kk

hep-th↗

arXiv2014

Emergent SUSY Theories: QED, SM & GUT

It might be expected that only global symmetries are fundamental symmetries of Nature, whereas local symmetries and associated massless gauge fields could solely emerge due to spontaneous breaking of underlying spacetime symmetries involved, such as relativistic invariance and supersymmetry. This breaking, taken in the form of the nonlinear sigma-model type pattern for vector fields or superfields, puts essential restrictions on geometrical degrees of freedom of a physical field system that makes it to adjust itself in such a way that its global internal symmetry G turns into the local symmetry G_{loc}. Remarkably, this emergence process may naturally be triggered by spontaneously broken supersymmetry, as is illustrated in detail by an example of a general supersymmetric QED model which is then extended to electroweak models and grand unified theories. Among others, the U(1)xSU(2) symmetrical Standard Model and flipped SU(5) GUT appear preferable to emerge at high energies.

hep-th↗

arXiv2014

Gauge Fields as Goldstone Bosons Triggered by Spontaneously Broken Supersymmetry

The emergent gauge theories are reconsidered in light of supersymmetry and an appropriate emergence conjecture is formulated. Accordingly, it might be expected that only global symmetries are fundamental symmetries of Nature, whereas local symmetries and associated massless gauge fields could solely emerge due to spontaneous breaking of underlying spacetime symmetries involved, such as relativistic invariance and supersymmetry. We further argue that this breaking, taken in the form of the nonlinear sigma-model type pattern for vector fields or superfields, puts essential restrictions on geometrical degrees of freedom of a physical field system that makes it to adjust itself in such a way that its global internal symmetry G turns into the local symmetry G_{loc}. Remarkably, this emergence process may naturally be triggered by supersymmetry, as is illustrated in detail by an example of a general supersymmetric QED model which is then extended to the Standard Model and GUTs. The requirement of vacuum stability in such class of models makes both Lorentz invariance and supersymmetry to become spontaneously broken in the visible sector. As a consequence, massless photon and other gauge bosons appear as the corresponding Goldstone and pseudo-Goldstone zero modes and special local invariance is simultaneously generated. Due to this invariance all possible Lorentz violations are turned out to be completely cancelled out among themselves. However, broken supersymmetry effects related to an existence of a light pseudo-goldstino (being essentially a photino) are still left in the theory. It typically appears in the low-energy particle spectrum as the eV scale stable LSP or the electroweak scale long-lived NLSP, being in both cases accompanied by a very light gravitino, that could be considered as some observational signature in favor of emergent supersymmetric theories.

hep-ph↗

arXiv2014

Photon and photino as Nambu-Goldstone zero modes in an emergent SUSY QED

We argue that supersymmetry with its well known advantages, such as naturalness, grand unification and dark matter candidate seems to possess one more attractive feature: it may trigger, through its own spontaneous violation in the visible sector, a dynamical generation of gauge fields as massless Nambu-Goldstone modes during which physical Lorentz invariance itself is ultimately preserved. We consider the supersymmetric QED model extended by an arbitrary polynomial potential of massive vector superfield that breaks gauge invariance in the SUSY invariant phase. However, the requirement of vacuum stability in such class of models makes both supersymmetry and Lorentz invariance to become spontaneously broken. As a consequence, massless photino and photon appear as the corresponding Nambu-Goldstone zero modes in an emergent SUSY QED, and also a special gauge invariance is simultaneously generated. Due to this invariance all observable relativistically noninvariant effects appear to be completely cancelled out among themselves and physical Lorentz invariance is recovered. Nevertheless, such theories may have an inevitable observational evidence in terms of the goldstino-photino like state presented in the low-energy particle spectrum. Its study is of a special interest for this class of SUSY models that, apart from some indication of an emergence nature of QED and the Standard Model, may appreciably extend the scope of SUSY breaking physics being actively studied in recent years.

hep-th↗

arXiv2013

On emergent SUSY gauge theories

We present the basic features of emergent SUSY gauge theories where an emergence of gauge bosons as massless vector Nambu-Goldstone modes is triggered by the spontaneously broken supersymmetry rather than the physically manifested Lorentz violation. We start considering the supersymmetric QED model extended by an arbitrary polynomial potential of massive vector superfield that induces the spontaneous SUSY violation in the visible sector. As a consequence, a massless photon appears as a companion of a massless photino emerging as a goldstino in the tree approximation, and remains massless due to the simultaneously generated special gauge invariance. This invariance is only restricted by the supplemented vector field constraint invariant under supergauge transformations. Meanwhile, photino being mixed with another goldstino appearing from a spontaneous SUSY violation in the hidden sector largely turns into the light pseudo-goldstino. Such pseudo-goldstonic photinos considered in an extended supersymmetric Standard Model framework are of a special observational interest that, apart from some indication of the QED emergence nature, may appreciably extend the scope of SUSY breaking physics being actively studied in recent years.

hep-ph↗

arXiv2013

Emergent gauge theories and supersymmetry: a QED primer

We argue that a generic trigger for photon and other gauge fields to emerge as massless Nambu-Goldstone modes could be spontaneously broken supersymmetry rather than physically manifested Lorentz violation. We consider supersymmetric QED model extended by an arbitrary polynomial potential of vector superfield that induces the spontaneous SUSY violation in the visible sector. As a consequence, massless photon appears as a companion of massless photino being Goldstone fermion state in tree approximation. Remarkably, the photon masslessness appearing at tree level is further protected against radiative corrections due to the simultaneously generated special gauge invariance in the broken SUSY phase. Meanwhile, photino being mixed with another goldstino appearing from a spontaneous SUSY violation in the hidden sector largely turns into light pseudo-goldstino whose physics seems to be of special interest.

hep-ph↗

arXiv2012

On Emergent Gauge and Gravity Theories

We present some general approach to emergent gauge theories and consider in significant detail the emergent tensor field gravity case. In essence, an arbitrary local theory of a symmetric two-tensor field $H_{μν}$ in Minkowski spacetime is considered, in which the equations of motion are required to be compatible with a nonlinear $σ$ model type length-fixing constraint $H_{μν}^{2}=\pm M^{2}$ leading to spontaneous Lorentz invariance violation, SLIV ($M$ is the proposed scale for SLIV). Allowing the parameters in the Lagrangian to be adjusted so as to be consistent with this constraint, the theory turns out to correspond to linearized general relativity in the weak field approximation, while some of the massless tensor Goldstone modes appearing through SLIV are naturally collected in the physical graviton. The underlying diffeomophism invariance emerges as a necessary condition for the tensor field $H_{μν}$ not to be superfluously restricted in degrees of freedom, apart from the constraint due to which the true vacuum in the theory is chosen by SLIV. The emergent theory appears essentially nonlinear, when expressed in terms of the pure Goldstone tensor modes and contains a plethora of new Lorentz and $CPT$ violating couplings. However, these couplings do not lead to physical Lorentz violation once this tensor field gravity is properly extended to conventional general relativity.

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