scholarly journals Duality-invariant extensions of Einstein-Maxwell theory

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Pablo A. Cano ◽  
Ángel Murcia
Keyword(s):  
Black Hole ◽  
Field Strength ◽  
Derivative Expansion ◽  
General Phenomenon ◽  
Maxwell Theory ◽  
Higher Derivative ◽  
Additional Constraints ◽  
General Duality ◽  
Black Hole Solutions ◽  
Weak Gravity

Abstract We investigate higher-derivative extensions of Einstein-Maxwell theory that are invariant under electromagnetic duality rotations, allowing for non-minimal couplings between gravity and the gauge field. Working in a derivative expansion of the action, we characterize the Lagrangians giving rise to duality-invariant theories up to the eight-derivative level, providing the complete list of operators that one needs to include in the action. We also characterize the set of duality-invariant theories whose action is quadratic in the Maxwell field strength but which are non-minimally coupled to the curvature. Then we explore the effect of field redefinitions and we show that, to six derivatives, the most general duality-preserving theory can be mapped to Maxwell theory minimally coupled to a higher-derivative gravity containing only four non-topological higher-order operators. We conjecture that this is a general phenomenon at all orders, i.e., that any duality-invariant extension of Einstein-Maxwell theory is perturbatively equivalent to a higher-derivative gravity minimally coupled to Maxwell theory. Finally, we study charged black hole solutions in the six-derivative theory and we investigate additional constraints on the couplings motivated by the weak gravity conjecture.

scholarly journals Causality of black holes in 4-dimensional Einstein–Gauss–Bonnet–Maxwell theory

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Xian-Hui Ge ◽  
Sang-Jin Sin
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Shear Viscosity ◽  
Upper Bound ◽  
Causal Structure ◽  
Density Ratio ◽  
Entropy Density ◽  
Coupling Constant ◽  
Maxwell Theory ◽  
Black Hole Solutions

Abstract We study charged black hole solutions in 4-dimensional (4D) Einstein–Gauss–Bonnet–Maxwell theory to the linearized perturbation level. We first compute the shear viscosity to entropy density ratio. We then demonstrate how bulk causal structure analysis imposes an upper bound on the Gauss–Bonnet coupling constant in the AdS space. Causality constrains the value of Gauss–Bonnet coupling constant $$\alpha _{GB}$$αGB to be bounded by $$\alpha _{GB}\le 0$$αGB≤0 as $$D\rightarrow 4$$D→4.

scholarly journals AdS black holes with higher derivative corrections in presence of string cloud

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Tanay K. Dey ◽  
Subir Mukhopadhyay
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gauge Theory ◽  
Binding Energy ◽  
Parameter Space ◽  
Bonnet Gravity ◽  
Higher Derivative ◽  
Ads Black Holes ◽  
Black Hole Solutions

AbstractWe consider asymptotically AdS black hole solutions in Einstein Gauss Bonnet gravity in presence of string clouds. As in the case of black hole solutions in Gauss Bonnet gravity, it admits three black hole solutions in presence of string clouds as well within a region of the parameter space. Using holography, we have studied the quark–antiquark distance and binding energy in the dual gauge theory.

scholarly journals Duality and supersymmetry constraints on the weak gravity conjecture

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Gregory J. Loges ◽  
Toshifumi Noumi ◽  
Gary Shiu
Keyword(s):  
Black Hole ◽  
Scattering Amplitudes ◽  
Energy Condition ◽  
Null Energy Condition ◽  
Black Hole Thermodynamics ◽  
Simple Condition ◽  
Mass Ratio ◽  
Higher Derivative ◽  
Bps States ◽  
Weak Gravity

Abstract Positivity bounds coming from consistency of UV scattering amplitudes are not always sufficient to prove the weak gravity conjecture for theories beyond Einstein-Maxwell. Additional ingredients about the UV may be necessary to exclude those regions of parameter space which are naïvely in conflict with the predictions of the weak gravity conjecture. In this paper we explore the consequences of imposing additional symmetries inherited from the UV theory on higher-derivative operators for Einstein-Maxwell-dilaton-axion theory. Using black hole thermodynamics, for a preserved SL(2, ℝ) symmetry we find that the weak gravity conjecture then does follow from positivity bounds. For a preserved O(d, d; ℝ) symmetry we find a simple condition on the two Wilson coefficients which ensures the positivity of corrections to the charge-to-mass ratio and that follows from the null energy condition alone. We find that imposing supersymmetry on top of either of these symmetries gives corrections which vanish identically, as expected for BPS states.

scholarly journals Electromagnetic quasitopological gravities

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Pablo A. Cano ◽  
Ángel Murcia
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Equations Of Motion ◽  
Analytic Solutions ◽  
Maxwell Theory ◽  
Fully Integrated ◽  
Higher Derivative ◽  
Metric Function ◽  
Minimal Mass ◽  
Extremal Black Holes

Abstract We identify a set of higher-derivative extensions of Einstein-Maxwell theory that allow for spherically symmetric charged solutions characterized by a single metric function f (r) = −gtt = 1/grr. These theories are a non-minimally coupled version of the recently constructed Generalized Quasitopological gravities and they satisfy a number of properties that we establish. We study magnetically-charged black hole solutions in these new theories and we find that for some of them the equations of motion can be fully integrated, enabling us to obtain analytic solutions. In those cases we show that, quite generally, the singularity at the core of the black hole is removed by the higher-derivative corrections and that the solution describes a globally regular geometry. In other cases, the equations are reduced to a second order equation for f (r). Nevertheless, for all the theories it is possible to study the thermodynamic properties of charged black holes analytically. We show that the first law of thermodynamics holds exactly and that the Euclidean and Noether-charge methods provide equivalent results. We then study extremal black holes, focusing on the corrections to the extremal charge-to-mass ratio at a non-perturbative level. We observe that in some theories there are no extremal black holes below certain mass. We also show the existence of theories for which extremal black holes do not represent the minimal mass state for a given charge. The implications of these findings for the evaporation process of black holes are discussed.

scholarly journals Holographic charge transport in 2+1 dimensions at finite N

2014 ◽  
Vol 29 (11n12) ◽  
pp. 1450061 ◽  
Author(s):  
Shan Bai ◽  
Da-Wei Pang
Keyword(s):  
Black Hole ◽  
Field Strength ◽  
Charge Transport ◽  
Weyl Tensor ◽  
Black Hole Solution ◽  
Low Frequency ◽  
Frequency Limit ◽  
Einstein Theory ◽  
Higher Derivative ◽  
Large Frequency

We study holographic charge transport in (2+1) dimensions at finite N, whose dual gravity background is given by perturbative black hole solution in Einstein theory plus cubic terms of Weyl tensor. We consider the higher derivative corrections to the standard Maxwell action, given by the interacting terms between the Weyl tensor and the field strength. We calculate the DC conductivity by using both the membrane paradigm and the Kubo's formula and find precise agreement. We compute the AC conductivity and find an analog of the crossover from "metal" to "bad metal" in the low frequency limit. Moreover, the conductivity becomes a constant in the large frequency limit. We derive two universal relations for the Green's functions and observe that they are exactly the same as the infinite N counterparts.

Lovelock black holes in the presence of nonlinear electrodynamics

2015 ◽  
Vol 24 (06) ◽  
pp. 1550040 ◽  
Author(s):  
Seyed Hossein Hendi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Nonlinear Electrodynamics ◽  
Thermodynamic Quantities ◽  
De Sitter ◽  
Maxwell Theory ◽  
Hole Radius ◽  
Higher Dimensional ◽  
Effective Cosmological Constant ◽  
Black Hole Solutions

In this paper, we consider third-order Lovelock–Maxwell gravity with additional (Fμν Fμν)2 term as a nonlinearity correction of the Maxwell theory. We obtain black hole solutions with various horizon topologies (and various number of horizons) in which their asymptotical behavior can be flat or anti-de Sitter with an effective cosmological constant. We investigate the effects of Lovelock and electrodynamic corrections on properties of the solutions. Then, we restrict ourselves to asymptotically flat solutions and calculate the conserved and thermodynamic quantities. We check the first law of thermodynamics for these black hole solutions and calculate the heat capacity to analyze stability. Although higher dimensional black holes in Einstein gravity are unstable, here we look for suitable constraints on the black hole radius to find thermally stable black hole solutions.

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