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Jiliang Jing - One of the best experts on this subject based on the ideXlab platform.

  • generalized superconductors from the coupling of a scalar field to the Einstein Tensor and their refractive index in massive gravity
    European Physical Journal C, 2019
    Co-Authors: Manman Sun, Dong Wang, Qiyuan Pan, Jiliang Jing
    Abstract:

    We construct the generalized superconductors from the coupling of a scalar field to the Einstein Tensor in the massive gravity and investigate their negative refraction in the probe limit. We observe that the larger graviton mass and Einstein Tensor coupling parameters both hinder the formation of the condensation, but the larger graviton mass or smaller coupling parameter makes it easier for the emergence of the Cave of Winds. Furthermore, we see that the larger graviton mass but smaller coupling parameter make the range of frequencies or the range of temperatures larger for which a negative Depine–Lakhtakia index occurs, which indicates that the graviton mass and Einstein Tensor have completely different effects on the negative refraction. In addition, we find that the larger graviton mass and coupling parameters both can reduce the dissipation and improve the propagation in the holographic setup.

  • backreacting holographic superconductors from the coupling of a scalar field to the Einstein Tensor
    Physics Letters B, 2018
    Co-Authors: Dong Wang, Manman Sun, Qiyuan Pan, Jiliang Jing
    Abstract:

    Abstract We investigate the properties of the backreacting holographic superconductors from the coupling of a scalar field to the Einstein Tensor in the background of a d-dimensional AdS black hole. Imposing the Dirichlet boundary condition of the trial function without the Neumann boundary conditions, we improve the analytical Sturm–Liouville method with an iterative procedure to explore the pure effect of the Einstein Tensor on the holographic superconductors and find that the Einstein Tensor hinders the condensate of the scalar field but does not affect the critical phenomena. Our analytical findings are in very good agreement with the numerical results from the “marginally stable modes” method, which implies that the Sturm–Liouville method is still powerful to study the holographic superconductors from the coupling of a scalar field to the Einstein Tensor even if we consider the backreactions.

  • chaos in the motion of a test scalar particle coupling to the Einstein Tensor in schwarzschild melvin black hole spacetime
    European Physical Journal C, 2017
    Co-Authors: Mingzhi Wang, Songbai Chen, Jiliang Jing
    Abstract:

    We present firstly the equation of motion for a test scalar particle coupling to the Einstein Tensor in the Schwarzschild–Melvin black hole spacetime through the short-wave approximation. Through analyzing Poincare sections, the power spectrum, the fast Lyapunov exponent indicator and the bifurcation diagram, we investigate the effects of the coupling parameter on the chaotic behavior of the particles. With the increase of the coupling strength, we find that the motion of the coupled particle for the chosen parameters becomes more regular and order for the negative couple constant. While, for the positive one, the motion of the coupled particles first undergoes a series of transitions betweens chaotic motion and regular motion and then falls into horizon or escapes to spatial infinity. Our results show that the coupling brings about richer effects for the motion of the particles.

  • chaos in the motion of a test scalar particle coupling to Einstein Tensor in schwarzschild melvin black hole spacetime
    arXiv: General Relativity and Quantum Cosmology, 2016
    Co-Authors: Mingzhi Wang, Songbai Chen, Jiliang Jing
    Abstract:

    We present firstly the equation of motion for a test scalar particle coupling to Einstein Tensor in the Schwarzschild-Melvin black hole spacetime through the short-wave approximation. Through analysing Poincare sections, the power spectrum, the fast Lyapunov exponent indicator and the bifurcation diagram, we investigate the effects of coupling parameter on the chaotic behavior of the particles. With the increase of the coupling strength, we find that the motion of coupled particle for the chosen parameters becomes more regular and order for the negative couple constant. While, for the positive one, the motion of coupled particles first undergoes a series of transitions between chaotic motion and regular motion and then falls into horizon or escapes to spatial infinite. Our results show that the coupling brings about richer effects for the motion of the particles.

  • black hole entropy arising from massless scalar field with lorentz violation induced by the coupling to Einstein Tensor
    Physics Letters B, 2015
    Co-Authors: Songbai Chen, Jiliang Jing, Hao Liao
    Abstract:

    Abstract We have investigated quantum entropy of a static black hole arising from the massless scalar field with Lorentz violation induced by the coupling to Einstein Tensor. Our results show that the coupled massless scalar field contributes to the classical Bekenstein–Hawking term in the black hole entropy. The corrected classical Bekenstein–Hawking entropy is not one quarter of the event horizon area of the original background black hole, but of a corresponding effective metric related to the coupling. It means that the classical Bekenstein–Hawking entropy depends not only on the black hole parameter, but also on the coupling which reduces Lorentz violation.

Eleftherios Papantonopoulos - One of the best experts on this subject based on the ideXlab platform.

  • instability of a reissner nordstrom ads black hole under perturbations of a scalar field coupled to the Einstein Tensor
    Physical Review D, 2019
    Co-Authors: Elcio Abdalla, Eleftherios Papantonopoulos, Bertha Cuadrosmelgar, R D B Fontana, Jeferson De Oliveira, A B Pavan
    Abstract:

    We study the instability of a Reissner-Nordstr\"om-AdS (RNAdS) black hole under perturbations of a massive scalar field coupled to Einstein Tensor. Calculating the potential of the scalar perturbations we find that as the strength of the coupling of the scalar to Einstein Tensor is increasing, the potential develops a negative well outside the black hole horizon, indicating an instability of the background RNAdS. We then investigate the effect of this coupling on the quasinormal modes. We find that there exists a critical value of the coupling that triggers the instability of the RNAdS. We also find that as the charge of the RNAdS is increased towards its extremal value, the critical value of the derivative coupling is decreased.

  • constraints on scalar Tensor theory of gravity by the recent observational results on gravitational waves
    European Physical Journal C, 2018
    Co-Authors: Yungui Gong, Eleftherios Papantonopoulos
    Abstract:

    The speed of gravitational waves provides us a new tool to test alternative theories of gravity. The constraint on the speed of gravitational waves from GW170817 and GRB170817A is used to test some classes of Horndeski theory. In particular, we consider the coupling of a scalar field to Einstein Tensor and the coupling of the Gauss–Bonnet term to a scalar field. The coupling strength of the Gauss–Bonnet coupling is constrained to be in the order of \(10^{-15}\). In the Horndeski theory we show that in order for this theory to satisfy the stringent constraint on the speed of GWs the mass scale M introduced in the non-minimally derivative coupling is constrained to be in the range \(10^{15} \,\,\text {GeV}\gg M \gtrsim 2\times 10^{-35}\) GeV taking also under consideration the early times upper bound for the mass scale M. The large mass ranges require no fine-tuning because the effect of non-minimally derivative coupling is negligible at late times.

  • gravitational collapse of a homogeneous scalar field coupled kinematically to Einstein Tensor
    Physical Review D, 2017
    Co-Authors: G Koutsoumbas, Eleftherios Papantonopoulos, Konstantinos Ntrekis, Minas Tsoukalas
    Abstract:

    We study the gravitational collapse of a homogeneous time-dependent scalar field that, besides its coupling to curvature, it is also kinematically coupled to the Einstein Tensor. This coupling is a part of the Horndeski theory and we investigate its effect on the collapsing process. We find that the time required for the scalar field to collapse depends on the value of the derivative coupling and the singularity is protected by a horizon. Matching the internal solution with an external Schwarzschild- AdS metric we show that a black hole is formed, while the weak energy condition is satisfied during the collapsing process. The scalar field takes on a finite value at the singularity.

  • building a holographic superconductor with a scalar field coupled kinematically to Einstein Tensor
    arXiv: High Energy Physics - Theory, 2016
    Co-Authors: Xiaomei Kuang, Eleftherios Papantonopoulos
    Abstract:

    We study the holographic dual description of a superconductor in which the gravity sector consists of a Maxwell field and a charged scalar field which except its minimal coupling to gravity it is also coupled kinematically to Einstein Tensor. As the strength of the new coupling is increased, the critical temperature below which the scalar field condenses is lowering, the condensation gap decreases faster than the temperature, the width of the condensation gap is not proportional to the size of the condensate and at low temperatures the condensation gap tends to zero for the strong coupling. These effects which are the result of the presence of the coupling of the scalar field to the Einstein Tensor in the gravity bulk, provide a dual description of impurities concentration in a superconducting state on the boundary.

  • scalar hair from a derivative coupling of a scalar field to the Einstein Tensor
    Classical and Quantum Gravity, 2012
    Co-Authors: Theodoros Kolyvaris, G Koutsoumbas, Eleftherios Papantonopoulos, George Siopsis
    Abstract:

    We consider a gravitating system of vanishing cosmological constant consisting of an electromagnetic field and a scalar field coupled to the Einstein Tensor. A Reissner–Nordstrom black hole undergoes a second-order phase transition to a hairy black hole of generally anisotropic hair at a certain critical temperature which we compute. The no-hair theorem is evaded due to the coupling between the scalar field and the Einstein Tensor. Within a first-order perturbative approach, we calculate explicitly the properties of a hairy black hole configuration near the critical temperature and show that it is energetically favourable over the corresponding Reissner–Nordstrom black hole.

Masato Minamitsuji - One of the best experts on this subject based on the ideXlab platform.

  • solutions in the generalized proca theory with the nonminimal coupling to the Einstein Tensor
    Physical Review D, 2016
    Co-Authors: Masato Minamitsuji
    Abstract:

    We investigate the static and spherically symmetric solutions in a class of the generalized Proca theory with the nonminimal coupling to the Einstein Tensor. First, we show that the solutions in the scalar-Tensor theory with the nonminimal derivative coupling to the Einstein Tensor can be those in the generalized Proca theory with the vanishing field strength. We then show that when the field strength takes the nonzero value the static and spherically symmetric solutions can be found only for the specific value of the nonminimal coupling constant. Second, we investigate the first-order slow-rotation corrections to the static and spherically symmetric background. We find that for the background with the vanishing electric field strength the slowly rotating solution is identical to the Kerr- (anti-) de Sitter solutions in general relativity. On the other hand, for the background with the nonvanishing electric field strength the stealth property can realized at the first order in the slow-rotation approximation.

  • causal structure in the scalar Tensor theory with field derivative coupling to the Einstein Tensor
    Physics Letters B, 2015
    Co-Authors: Masato Minamitsuji
    Abstract:

    a r t i c l e i n f o a b s t r a c t We investigate the causal structure in the scalar-Tensor theory with the field derivative coupling to the Einstein Tensor, which is a class of the Horndeski theory in the four-dimensional spacetime. We show that in general the characteristic hypersurface is non-null, which admits the superluminal propagations. We also derive the conditions that the characteristic hypersurface becomes null and show that a Killing horizon can be the causal edge for all the propagating degrees of freedom, if the additional conditions for the scalar field are satisfied. Finally, we find the position of the characteristic hypersurface in the dynamical spacetime with the maximally symmetric space, and that the fastest propagation can be su- perluminal, especially if the coupling constant becomes positive. We also argue that the superluminality itself may not lead to the acausality of the theory. © 2015 The Author. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP 3 .

  • Black hole quasinormal modes in a scalar-Tensor theory with field derivative coupling to the Einstein Tensor
    General Relativity and Gravitation, 2014
    Co-Authors: Masato Minamitsuji
    Abstract:

    We investigate the quasinormal modes of a test massless, minimally coupled scalar field on a static and spherically symmetric black hole in the scalar-Tensor theory with field derivative coupling to the Einstein Tensor, which is a part of the Horndeski theory with the shift symmetry. In our solution, the spacetime is asymptotically anti-de Sitter (AdS), where the effective AdS curvature scale is determined solely by the derivative coupling constant. The metric approaches the AdS spacetime in the asymptotic infinity limit and precisely recovers the Schwarzschild–AdS solution in general relativity if the coupling constant is tuned to the inverse of the cosmological constant. We numerically find the lowest lying quasinormal frequency for the perturbation about a test massless, minimally coupled scalar field. The quasinormal frequency agrees with that of the Schwarzschild–AdS solution for the tuned case. For other parameters, in the large black hole limit, as the metric coincides with that of the Schwarzschild–AdS black hole, the quasinormal frequency almost agrees with that of the Schwarzschild–AdS black hole and is insensitive to the value of the cosmological constant. On the other hand, for a small back hole the real part of the quasinormal frequency decreases as the absolute value of the cosmological constant increases.

  • braneworlds with field derivative coupling to the Einstein Tensor
    Physical Review D, 2014
    Co-Authors: Masato Minamitsuji
    Abstract:

    In this paper, we investigate the Randall-Sundrum type braneworld models in the scalar-Tensor theory with field derivative coupling to the Einstein Tensor. We first formulate the generalized junction conditions of the metric and the scalar field on the timelike codimension-one hypersurface (=brane). With the use of these junction conditions, we then derive the Minkowski and de Sitter brane solutions embedded into the $Z_2$-symmetric five-dimensional anti-de Sitter (AdS) bulk spacetime. The configuration of the scalar field depends on the slice of the AdS spacetime. These branes are supported by the tension and not coupled to the scalar field. The Minkowski brane solution can be obtained when the brane tension is tuned to the bulk contributions. Once this tuning relation is broken, the de Sitter brane solutions are obtained. The de Sitter brane solutions have two branches. One has the smooth limit to the case where the scalar field becomes trivial, while the other branch does not. The latter branch has the upper bound on the brane tension, where the expansion rate vanishes. Finally, we investigate the low energy effective gravitational theory realized on the brane, which is given by the four-dimensional Einstein-scalar theory with the corrections from the bulk. In the case that there is no generation of the dark radiation from the bulk scalar field, we recover the the four-dimensional Einstein-scalar theory.

M Gunaydin - One of the best experts on this subject based on the ideXlab platform.

  • gauging the full r symmetry group in five dimensional n 2 yang mills Einstein Tensor supergravity
    Physical Review D, 2001
    Co-Authors: M Gunaydin, Marco Zagermann
    Abstract:

    We show that certain five dimensional, N=2 Yang-Mills/Einstein supergravity theories admit the gauging of the full R-symmetry group, SU(2)_R, of the underlying N=2 Poincare superalgebra. This generalizes the previously studied Abelian gaugings of U(1)_R subgroup of SU(2)_R and completes the construction of the most general vector and Tensor field coupled five dimensional N=2 supergravity theories with gauge interactions. The gauging of SU(2)_R turns out to be possible only in special cases, and leads to a new type of scalar potential. For a large class of these theories the potential does not have any critical points.

  • vacua of 5d n 2 gauged yang mills Einstein Tensor supergravity abelian case
    Physical Review D, 2000
    Co-Authors: M Gunaydin, Marco Zagermann
    Abstract:

    We give a detailed study of the critical points of the potentials of the simplest nontrivial $\mathcal{N}=2$ gauged Yang-Mills-Einstein supergravity theories with Tensor multiplets. The scalar field target space of these examples is $\mathrm{SO}(1,1)\ifmmode\times\else\texttimes\fi{}\mathrm{SO}(2,1)/\mathrm{SO}(2.)$ The possible gauge groups are $\mathrm{SO}(2)\ifmmode\times\else\texttimes\fi{}\mathrm{U}{(1)}_{R}$ and $\mathrm{SO}(1,1)\ifmmode\times\else\texttimes\fi{}\mathrm{U}{(1)}_{R},$ where $\mathrm{U}{(1)}_{R}$ is a subgroup of the R-symmetry group $\mathrm{SU}{(2)}_{R},$ and $\mathrm{SO}(2)$ and $\mathrm{SO}(1,1)$ are subgroups of the isometry group of the scalar manifold. The scalar potentials of these theories consist of a contribution from the $\mathrm{U}{(1)}_{R}$ gauging and a contribution that is due to the presence of the Tensor fields. We find that the latter contribution can change the form of the supersymmetric extrema from maxima to saddle points. In addition, it leads to novel critical points not present in the corresponding gauged Yang-Mills-Einstein supergravity theories without the Tensor multiplets. For the $\mathrm{SO}(2)\ifmmode\times\else\texttimes\fi{}\mathrm{U}{(1)}_{R}$ gauged theory these novel critical points correspond to anti\char21{}de Sitter ground states. For the noncompact $\mathrm{SO}(1,1)\ifmmode\times\else\texttimes\fi{}\mathrm{U}{(1)}_{R}$ gauging, the novel ground states are de Sitter ground states. The analysis of the critical points of the potential carries over in a straightforward manner to the generic family of $\mathcal{N}=2$ gauged Yang-Mills-Einstein supergravity theories with Tensor multiplets whose scalar manifolds are of the form $\mathrm{SO}(1,1)\ifmmode\times\else\texttimes\fi{}\mathrm{SO}(n\ensuremath{-}1,1)/\mathrm{SO}(n\ensuremath{-}1).$

Songbai Chen - One of the best experts on this subject based on the ideXlab platform.

  • chaos in the motion of a test scalar particle coupling to the Einstein Tensor in schwarzschild melvin black hole spacetime
    European Physical Journal C, 2017
    Co-Authors: Mingzhi Wang, Songbai Chen, Jiliang Jing
    Abstract:

    We present firstly the equation of motion for a test scalar particle coupling to the Einstein Tensor in the Schwarzschild–Melvin black hole spacetime through the short-wave approximation. Through analyzing Poincare sections, the power spectrum, the fast Lyapunov exponent indicator and the bifurcation diagram, we investigate the effects of the coupling parameter on the chaotic behavior of the particles. With the increase of the coupling strength, we find that the motion of the coupled particle for the chosen parameters becomes more regular and order for the negative couple constant. While, for the positive one, the motion of the coupled particles first undergoes a series of transitions betweens chaotic motion and regular motion and then falls into horizon or escapes to spatial infinity. Our results show that the coupling brings about richer effects for the motion of the particles.

  • chaos in the motion of a test scalar particle coupling to Einstein Tensor in schwarzschild melvin black hole spacetime
    arXiv: General Relativity and Quantum Cosmology, 2016
    Co-Authors: Mingzhi Wang, Songbai Chen, Jiliang Jing
    Abstract:

    We present firstly the equation of motion for a test scalar particle coupling to Einstein Tensor in the Schwarzschild-Melvin black hole spacetime through the short-wave approximation. Through analysing Poincare sections, the power spectrum, the fast Lyapunov exponent indicator and the bifurcation diagram, we investigate the effects of coupling parameter on the chaotic behavior of the particles. With the increase of the coupling strength, we find that the motion of coupled particle for the chosen parameters becomes more regular and order for the negative couple constant. While, for the positive one, the motion of coupled particles first undergoes a series of transitions between chaotic motion and regular motion and then falls into horizon or escapes to spatial infinite. Our results show that the coupling brings about richer effects for the motion of the particles.

  • black hole entropy arising from massless scalar field with lorentz violation induced by the coupling to Einstein Tensor
    Physics Letters B, 2015
    Co-Authors: Songbai Chen, Jiliang Jing, Hao Liao
    Abstract:

    Abstract We have investigated quantum entropy of a static black hole arising from the massless scalar field with Lorentz violation induced by the coupling to Einstein Tensor. Our results show that the coupled massless scalar field contributes to the classical Bekenstein–Hawking term in the black hole entropy. The corrected classical Bekenstein–Hawking entropy is not one quarter of the event horizon area of the original background black hole, but of a corresponding effective metric related to the coupling. It means that the classical Bekenstein–Hawking entropy depends not only on the black hole parameter, but also on the coupling which reduces Lorentz violation.

  • dynamical evolution of a vector field perturbation coupled to the Einstein Tensor
    Physical Review D, 2014
    Co-Authors: Songbai Chen, Jiliang Jing
    Abstract:

    We have investigated the wave dynamics of a vector field perturbation coupling to the Einstein Tensor in the four-dimensional Reissner-Nordstrom black hole spacetime. Our results show that besides the dependence on the coupling between the vector field and Einstein Tensor, the wave dynamic equation of the vector field perturbation strongly depends on the parity of the perturbation itself, which is quite different from that of the usual vector field perturbation without the coupling in the four-dimensional spacetime. Moreover, we also find that the vector field perturbation with odd parity grows with an exponential rate if the coupling strength is stronger than a certain critical value. However, the vector field perturbation with even parity always decays in the Reissner-Nordstrom black hole spacetime.