We study the scalar, vector and tensor two-gluon and trigluon glueball spectra in the framework of the 5-dimension dynamical holographic QCD model, where the metric structure is deformed self-consistently by the dilat...We study the scalar, vector and tensor two-gluon and trigluon glueball spectra in the framework of the 5-dimension dynamical holographic QCD model, where the metric structure is deformed self-consistently by the dilaton field. For comparison, the glueball spectra are also calculated in the hard-wall and soft-wall holographic QCD models. In order to distinguish glueballs with even and odd parities, we introduce a positive and negative coupling between the dilaton field and glueballs, and for higher spin glueballs, we introduce a deformed 5-dimension mass. With this set-up, there is only one free parameter from the quadratic dilaton profile in the dynamical holographic QCD model, which is fixed by the scalar glueball spectra. It is found that the two-gluon glueball spectra produced in the dynamical holographic QCD model are in good agreement with lattice data. Among six trigluon glueballs, the produced masses for 1±- and 2-- are in good agreement with lattice data, and the produced masses for 0--, 0＋- and 2＋- are around 1.5 GeV lighter than lattice results. This result might indicate that the three trigluon glueballs of 0--, 0＋- and 2＋- are dominated by the three-gluon condensate contribution.展开更多
We discuss, giving all necessary details, the boundary-bulk propagators. We do it for a scalar field, with and without mass, for both the Feynman and the Wheeler cases. Contrary to standard procedure, we do not need h...We discuss, giving all necessary details, the boundary-bulk propagators. We do it for a scalar field, with and without mass, for both the Feynman and the Wheeler cases. Contrary to standard procedure, we do not need here to appeal to any unfounded conjecture (as done by other authors). Emphasize that we do not try to modify standard ADS/CFT procedures, but use them to evaluate the corresponding Feynman and Wheeler propagators. Our present calculations are original in the sense of being the first ones undertaken explicitly using distributions theory (DT). They are carried out in two instances: 1) when the boundary is a Euclidean space and 2) when it is of Minkowskian nature. In this last case we compute also three propagators: Feynman’s, Anti-Feynman’s, and Wheeler’s (half advanced plus half retarded). For an operator corresponding to a scalar field we explicitly obtain, for the first time ever, the two points’ correlations functions in the three instances above mentioned. To repeat, it is not our intention here to improve on ADS/CFT theory but only to employ it for evaluating the corresponding Wheeler’s propagators.展开更多
In this topic review,we introduce recent developments on holographic entanglement entropy.After briefly reviewing the basic notions of entanglement in quantum information and quantum field theory,we introduce the RyuT...In this topic review,we introduce recent developments on holographic entanglement entropy.After briefly reviewing the basic notions of entanglement in quantum information and quantum field theory,we introduce the RyuTakayanagi’s prescription of computing the entanglement entropy holographically.We review the inequalities on the holographic entanglement entropy,and its derivation from Euclidean gravity.In particular,we discuss its implications in semi-classical AdS3/CFT2 correspondence,and furthermore review the recent studies on the emergence of geometry and gravity from entanglement.展开更多
Recent discussions attributed fermion mass to an analogue of Weyl curvature which occurred by hypothesis when closed, spin strings swept out closed world tubes. A new degree of freedom and corresponding curvature clas...Recent discussions attributed fermion mass to an analogue of Weyl curvature which occurred by hypothesis when closed, spin strings swept out closed world tubes. A new degree of freedom and corresponding curvature class were attributed to “second order tubes” that were swept out by initially introduced closed tubes, etc. Curvature classes were associated by hypothesis with composite masses where d enoted a mass-less spin field and where a and respectively denoted an LH quark and an RH anti-lepton that were characterized by opposite I3 values and shared a common generation. The resulting model accounted for known quark masses and predicted a new quark of mass 30 GeV/c2. The composite masses form a symmetry, the preservation of which is equivalent to the conservation of electrical charge and string scale. SUGRA interactions that preserve the proposed symmetry can therefore be precisely defined. In this context, gauge transformations that establish the proposed curvature classes also associate with a second realization of the originally generated symmetry, the preservation of which is equivalent to the conservation of string length and of the curvature ?from which the postulated model generates admissible increments of large scale expansion. The latter symmetry is associated by hypothesis with the large scale structure of the observable universe, thereby motivating a theoretical approximation of the total number of galaxies. This result parallels the approximation that is indicated by observation.展开更多
In this work,we study the effects of the Weyl corrections on the p-wave superfluid phase transition in terms of an EinsteinMaxwell theory coupled to a complex vector field.In the probe limit,it is observed that the ph...In this work,we study the effects of the Weyl corrections on the p-wave superfluid phase transition in terms of an EinsteinMaxwell theory coupled to a complex vector field.In the probe limit,it is observed that the phase structure is significantly modified owing to the presence of the higher order Weyl corrections.The latter,in general,facilitates the emergence of the superfluid phase as the condensate increases with the Weyl coupling measured byγ.Moreover,several features about the phase structure of the holographic superfluid are carefully investigated.In a specific region,the phase transition from the normal phase to the superfluid phase is identified to be the first order,instead of being the second order,as in the cases for many holographic superconductors.By carrying out a numerical scan of model parameters,the boundary dividing these two types of transitions is located and shown to be rather sensitive to the strength of Weyl coupling.Also,a feature known as"Cave of Winds",associated with the emergence of a second superfluid phase,is observed for specific choices of model parameters.However,it becomes less prominent and eventually disappears asγincreases.Furthermore,for temperature in the vicinity of the critical one for vanishing superfluid velocity,denoted by T0,the supercurrent is found to be independent of the Weyl coupling.The calculated ratio,of the condensate with vanishing superfluid velocity to that with maximal superfluid velocity,is in good agreement with that predicted by Ginzburg-Landau theory.While compared with the impact on the phase structure owing to the higher curvature corrections,the findings in our present study demonstrate entirely different characteristics.Further implications are discussed.展开更多
We investigate the exact results for circular 1/4 and 1/2 BPS Wilson loops in the d = 3 N = 4 super Chern-Simons-matter theory that could be obtained by orbifolding Aharony-Bergman-Jafferis-Maldacena （ABJM） theory. ...We investigate the exact results for circular 1/4 and 1/2 BPS Wilson loops in the d = 3 N = 4 super Chern-Simons-matter theory that could be obtained by orbifolding Aharony-Bergman-Jafferis-Maldacena （ABJM） theory. The partition function of the Af = 4 orbifold ABJM theory has been computed previously in the literature. In this paper, we re-derive it using a slightly different method. We calculate the vacuum expectation values of the circular 1/4 BPS Wilson loops in fundamental representation and of circular 1/2 BPS Wilson loops in arbitrary representations. We use both the saddle point approach and Fermi gas approach. The results for Wilson loops are in accord with the available gravity results.展开更多
We apply an AdS/CFT-inspired color-dipole model which contains only three free parameters to describe the HERA data for the inclusive structure function F 2 at small Bjorken-x and virtuality.We found that the saturati...We apply an AdS/CFT-inspired color-dipole model which contains only three free parameters to describe the HERA data for the inclusive structure function F 2 at small Bjorken-x and virtuality.We found that the saturation scale in our AdS/CFT-based parameterization varies in the range of 1 ÷ 3 GeV becoming independent of energy/Bjorken-x at very small x.This leads to the prediction of x-independence of the structure functions at very small x.With the fitted parameters in our model,the predictions for F 2,longitudinal structure function,charm structure function and total photo-production cross-sections in the kinematic regions of future experiments can be given.展开更多
基金Supported by the NSFC(11175251,11621131001)DFG and NSFC(CRC 110)+1 种基金CAS Key Project KJCX2-EW-N01,K.C.Wong Education FoundationYouth Innovation Promotion Association of CAS
文摘We study the scalar, vector and tensor two-gluon and trigluon glueball spectra in the framework of the 5-dimension dynamical holographic QCD model, where the metric structure is deformed self-consistently by the dilaton field. For comparison, the glueball spectra are also calculated in the hard-wall and soft-wall holographic QCD models. In order to distinguish glueballs with even and odd parities, we introduce a positive and negative coupling between the dilaton field and glueballs, and for higher spin glueballs, we introduce a deformed 5-dimension mass. With this set-up, there is only one free parameter from the quadratic dilaton profile in the dynamical holographic QCD model, which is fixed by the scalar glueball spectra. It is found that the two-gluon glueball spectra produced in the dynamical holographic QCD model are in good agreement with lattice data. Among six trigluon glueballs, the produced masses for 1±- and 2-- are in good agreement with lattice data, and the produced masses for 0--, 0＋- and 2＋- are around 1.5 GeV lighter than lattice results. This result might indicate that the three trigluon glueballs of 0--, 0＋- and 2＋- are dominated by the three-gluon condensate contribution.
文摘We discuss, giving all necessary details, the boundary-bulk propagators. We do it for a scalar field, with and without mass, for both the Feynman and the Wheeler cases. Contrary to standard procedure, we do not need here to appeal to any unfounded conjecture (as done by other authors). Emphasize that we do not try to modify standard ADS/CFT procedures, but use them to evaluate the corresponding Feynman and Wheeler propagators. Our present calculations are original in the sense of being the first ones undertaken explicitly using distributions theory (DT). They are carried out in two instances: 1) when the boundary is a Euclidean space and 2) when it is of Minkowskian nature. In this last case we compute also three propagators: Feynman’s, Anti-Feynman’s, and Wheeler’s (half advanced plus half retarded). For an operator corresponding to a scalar field we explicitly obtain, for the first time ever, the two points’ correlations functions in the three instances above mentioned. To repeat, it is not our intention here to improve on ADS/CFT theory but only to employ it for evaluating the corresponding Wheeler’s propagators.
基金Supported by the Special Fund for Theoretical Physics from the Natural Science Foundations of China under Grant No.11747606National Natural Science Foundation of China under Grant Nos.11275010,11335012,11325522,and 11735001
文摘In this topic review,we introduce recent developments on holographic entanglement entropy.After briefly reviewing the basic notions of entanglement in quantum information and quantum field theory,we introduce the RyuTakayanagi’s prescription of computing the entanglement entropy holographically.We review the inequalities on the holographic entanglement entropy,and its derivation from Euclidean gravity.In particular,we discuss its implications in semi-classical AdS3/CFT2 correspondence,and furthermore review the recent studies on the emergence of geometry and gravity from entanglement.
文摘Recent discussions attributed fermion mass to an analogue of Weyl curvature which occurred by hypothesis when closed, spin strings swept out closed world tubes. A new degree of freedom and corresponding curvature class were attributed to “second order tubes” that were swept out by initially introduced closed tubes, etc. Curvature classes were associated by hypothesis with composite masses where d enoted a mass-less spin field and where a and respectively denoted an LH quark and an RH anti-lepton that were characterized by opposite I3 values and shared a common generation. The resulting model accounted for known quark masses and predicted a new quark of mass 30 GeV/c2. The composite masses form a symmetry, the preservation of which is equivalent to the conservation of electrical charge and string scale. SUGRA interactions that preserve the proposed symmetry can therefore be precisely defined. In this context, gauge transformations that establish the proposed curvature classes also associate with a second realization of the originally generated symmetry, the preservation of which is equivalent to the conservation of string length and of the curvature ?from which the postulated model generates admissible increments of large scale expansion. The latter symmetry is associated by hypothesis with the large scale structure of the observable universe, thereby motivating a theoretical approximation of the total number of galaxies. This result parallels the approximation that is indicated by observation.
基金National Natural Science Foundation of China(Grant Nos.11775076,11875025,11475061,and 11690034)Hunan Provincial Natural Science Foundation of China(Grant No.2016JJ1012)+2 种基金Brazilian funding agencies Fundacao de AmparoàPesquisa do Estado de Sao Paulo(FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nível Superior(CAPES)。
文摘In this work,we study the effects of the Weyl corrections on the p-wave superfluid phase transition in terms of an EinsteinMaxwell theory coupled to a complex vector field.In the probe limit,it is observed that the phase structure is significantly modified owing to the presence of the higher order Weyl corrections.The latter,in general,facilitates the emergence of the superfluid phase as the condensate increases with the Weyl coupling measured byγ.Moreover,several features about the phase structure of the holographic superfluid are carefully investigated.In a specific region,the phase transition from the normal phase to the superfluid phase is identified to be the first order,instead of being the second order,as in the cases for many holographic superconductors.By carrying out a numerical scan of model parameters,the boundary dividing these two types of transitions is located and shown to be rather sensitive to the strength of Weyl coupling.Also,a feature known as"Cave of Winds",associated with the emergence of a second superfluid phase,is observed for specific choices of model parameters.However,it becomes less prominent and eventually disappears asγincreases.Furthermore,for temperature in the vicinity of the critical one for vanishing superfluid velocity,denoted by T0,the supercurrent is found to be independent of the Weyl coupling.The calculated ratio,of the condensate with vanishing superfluid velocity to that with maximal superfluid velocity,is in good agreement with that predicted by Ginzburg-Landau theory.While compared with the impact on the phase structure owing to the higher curvature corrections,the findings in our present study demonstrate entirely different characteristics.Further implications are discussed.
基金Supported by NSFC(11222549,11575202)K.C.Wong Education FoundationYouth Innovation Promotion Association of CAS(2011016)
文摘We investigate the exact results for circular 1/4 and 1/2 BPS Wilson loops in the d = 3 N = 4 super Chern-Simons-matter theory that could be obtained by orbifolding Aharony-Bergman-Jafferis-Maldacena （ABJM） theory. The partition function of the Af = 4 orbifold ABJM theory has been computed previously in the literature. In this paper, we re-derive it using a slightly different method. We calculate the vacuum expectation values of the circular 1/4 BPS Wilson loops in fundamental representation and of circular 1/2 BPS Wilson loops in arbitrary representations. We use both the saddle point approach and Fermi gas approach. The results for Wilson loops are in accord with the available gravity results.
基金Supported by PBCT Project (ACT/028 'Center of Atomic Physics')FONDECYT (Chile) Project (11090085)
文摘We apply an AdS/CFT-inspired color-dipole model which contains only three free parameters to describe the HERA data for the inclusive structure function F 2 at small Bjorken-x and virtuality.We found that the saturation scale in our AdS/CFT-based parameterization varies in the range of 1 ÷ 3 GeV becoming independent of energy/Bjorken-x at very small x.This leads to the prediction of x-independence of the structure functions at very small x.With the fitted parameters in our model,the predictions for F 2,longitudinal structure function,charm structure function and total photo-production cross-sections in the kinematic regions of future experiments can be given.
