Effect Of Higher Derivative Corrections Research Articles

Strong cosmic censorship for a scalar field in an Einstein-Maxwell-Gauss-Bonnet-de Sitter black hole * *This work is supported in part by NSFC (11005016, 11875196, 11375121)

It has been shown that the Christodoulou version of the strong cosmic censorship (SCC) conjecture can be violated for a scalar field in a near-extremal Reissner-Nordstrom-de Sitter black hole. In this paper, we investigate the effects of higher derivative corrections to the Einstein-Hilbert action on the validity of SCC, by considering a neutral massless scalar perturbation in - and -dimensional Einstein-Maxwell-Gauss-Bonnet-de Sitter black holes. Our numerical results show that the higher derivative term plays a different role in the case than it does in the case. For , the SCC violation region increases as the strength of the higher derivative term increases. For , the SCC violation region first increases and then decreases as the higher derivative correction becomes stronger, and SCC can always be restored for a black hole with a fixed charge ratio when the higher derivative correction is strong enough. Finally, we find that the version of SCC is respected in the case, but can be violated in some near-extremal regimes in the case.

Probing strongly coupled anisotropic plasmas from higher curvature gravity

We consider five-dimensional AdS-axion-dilaton gravity with a Gauss-Bonnet term and use a black brane solution displaying spatial anisotropy as the gravity dual of a strongly coupled anisotropic plasma. We compute several observables relevant to the study of the plasma, namely, the drag force, the jet quenching parameter, the quarkonium potential and the thermal photon production. The effects of higher derivative corrections and of the anisotropy are discussed and compared with previous results.

The Effect of Higher Derivative Correction on η/s and Conductivities in STU Model

In this paper we study the ratio of shear viscosity to entropy, electrical and thermal conductivities for the R-charged black hole in STU model. We generalize previous works to the case of a black hole with three different charges. Actually we use diffusion constant to obtain ratio of shear viscosity to entropy. By applying the thermodynamical stability we recover previous results. Also we investigate the effect of higher derivative corrections.

EVH black hole solutions with higher derivative corrections

We analyze the effect of higher derivative corrections to the near horizon geometry of the extremal vanishing horizon (EVH) black hole solutions in four dimensions. We restrict ourselves to the Gauss-Bonnet correction with a dilation dependent coupling in an Einstein Maxwell dilaton theory. This action may represent the effective action as it arises in tree level heterotic string theory compactified to four dimensions or the K3 compactification of type II string theory. We show that EVH black holes, in this theory, develop an AdS3 throat in their near horizon geometry.

Drag force with different charges in STU background and AdS/CFT

In this paper we consider the drag force problem in the STU model. This problem and related topics were already studied in SYM theory. Here we study the same problem in supergravity theory with an R-charge black hole (the STU model). This paper extends our previous work (Sadeghi J and Pourhassan B 2008 J. High Energy Phys. JHEP12(2008)026; Sadeghi J, Setare M R, Pourhassan B and Hashmatian S 2009 Eur. Phys. J. C 61 527) by studying more general charge configurations and by taking into account the effect of a constant electromagnetic field and higher derivative corrections. We consider a single quark and a pair in a three-charge non-extremal black hole background. First, by using the AdS/CFT correspondence, we obtain the drag force, the diffusion coefficient, the total energy and momentum, quasi-normal modes and the effect of higher derivative corrections for the single quark. Next we calculate the drag force for a pair which rotates around its center of mass. For the first time we study the motion of a rotating pair in this background. We show that our results in the near-extremal limit and finite chemical potential agree with the energy loss of the moving quark which was calculated in the SYM plasma.

Higher derivative effects onη/sat finite chemical potential

We examine the effects of higher derivative corrections on η/s, the ratio of shear viscosity to entropy density, in the case of a finite R-charge chemical potential. In particular, we work in the framework of five-dimensional N = 2 gauged supergravity, and include terms up to four derivatives, representing the supersymmetric completion of the Chern-Simons term A Λ Tr(R Λ R). The addition of the four-derivative terms yields a correction which is a 1/N effect, and in general gives rise to a violation of the η/s bound. Furthermore, we find that, once the bound is violated, turning on the chemical potential only leads to an even larger violation of the bound.

Higher derivative corrections, dimensional reduction and Ehlers duality

Motivated by applications to black hole physics and duality, we study the effect of higher derivative corrections on the dimensional reduction of four-dimensional Einstein, Einstein-Liouville and Einstein-Maxwell gravity to one direction, as appropriate for stationary, spherically symmetric solutions. We construct a field redefinition scheme such that the one-dimensional Lagrangian is corrected only by powers of first derivatives of the fields, eliminating spurious modes and providing a suitable starting point for quantization. We show that the Ehlers symmetry, broken by the leading R2 corrections in Einstein-Liouville gravity, can be restored by including contributions of Taub-NUT instantons. Finally, we give a preliminary discussion of the duality between higher-derivative F-term corrections on the vector and hypermultiplet branches in N = 2 supergravity in four dimensions.