Born-Infeld Nonlinear Electrodynamics Research Articles

Existence of solutions of exponential model in Born–Infeld nonlinear electrodynamics

In this paper, we discuss the existence of solutions to a nonlinear problem involving an exponential model of the Born–Infeld nonlinear electromagnetism. We establish an existence theorem by variational methods and mathematical analysis. We also show that the solutions obtained are nonnegative.

Electromagnetic asymmetry, relegation of curvature singularities of charged black holes, and cosmological equations of state in view of the Born–Infeld theory

It is shown that the Born–Infeld nonlinear electrodynamics with a polynomial type nonlinearity accommodates finite-energy electric point charges but rejects finite-energy magnetic point charges, or monopoles, thereby spelling out an electromagnetic asymmetry. Moreover, it is demonstrated, in a systematic way, that the curvature singularities of finite-energy charged black holes in the context of the Born–Infeld theory may effectively be relegated or in some cases removed under a critical mass–energy condition, which has been employed successfully in earlier concrete studies. Furthermore, it is illustrated through numerous examples considered here that, when adapted to describe scalar-wave matters known as k-essences, the Born–Infeld formalism provides a fertile ground for cosmological applications, including achieving accelerated dark-energy expansions and acquiring adequate field-theoretical realizations of the equations of state of various cosmic fluid models.

Emergence of non-linear electrodynamic theories from [formula omitted]-like deformations

In this letter, we investigate the deformation of the ModMax theory, as a unique Lagrangian of non-linear electrodynamics preserving both conformal and electromagnetic-duality invariance, under TT¯-like flows. We will show that the deformed theory is the generalized non-linear Born-Infeld electrodynamics. Being inspired by the invariance under the flow equation for Born-Infeld theories, we propose another TT¯-like operator generating the ModMax and generalized Born-Infeld non-linear electrodynamic theories from the usual Maxwell and Born-Infeld theories, respectively.

Complexity for holographic superconductors with the nonlinear electrodynamics

We systematically study the complexity of a strip-shaped subregion in a fully backreacted holographic model of a superconductor with the nonlinear electrodynamics by the “complexity=volume” (CV) conjecture, and compare it with the holographic entanglement entropy. We consider three types of typical nonlinear electrodynamics and find that the holographic complexity can be utilized as a good probe of the superconductor phase transition in the nonlinear electrodynamics like the holographic entanglement entropy does. For the operator O−, the complexity decreases (or increases) monotonically as the absolute value of the nonlinear parameter |b| grows in the superconducting (or normal) phase, which is the opposite of the behavior of the holographic entanglement entropy, and this property holds for various types of the nonlinear electrodynamics. For the operator O+, in the superconducting phase, it is interesting to note that the complexity is a monotonic decreasing function of |b| for the Logarithmic nonlinear electrodynamics (LNE), but in systems with the Born-Infeld nonlinear electrodynamics (BINE) and Exponential nonlinear electrodynamics (ENE), as the parameter |b| increases, the complexity first decreases and arrives at its minimum at some threshold, then increases monotonously. Whereas the non-monotonic variation of the holographic entanglement entropy can be seen in all the three types of the nonlinear electrodynamics, concretely, it first rises, then descends with larger |b|, and has a peak at the inflection point. Furthermore, comparing with the BINE and LNE, we find that the ENE has stronger effect on the condensation formation, the subregion complexity and the entanglement entropy of the holographic superconductors with backreaction.

Shadow, deflection angle and quasinormal modes of Born-Infeld charged black holes

In this paper, we consider black holes in the consistent Aoki-Gorji-Mukohyama theory of the four-dimensional Einstein-Gauss-Bonnet (4D EGB) gravity in the presence of Born-Infeld (BI) nonlinear electrodynamics. We study several optical features of these black holes such as the shadow radius, energy emission rate and deflection angle, and analyse the effect of the coupling constants, the electric charge and cosmological constant on the considered optical quantities. Furthermore, we also employ the connection between the shadow radius and quasinormal modes (QNMs) and investigate small scalar perturbations around the black hole solution. We show that the variation of the parameters of the theory provide specific signatures on the optical features of the BI charged black hole solution, thus leading to the possibility of directly testing this consistent Aoki-Gorji-Mukohyama 4D EGB black hole model by using astrophysical observations.

Teleparallel gravity coupled to matter content from nonlinear electrodynamics with dyonic configuration

This paper considers a static, spherically symmetric spacetime in the context of teleparallel equivalent of General Relativity coupled to the matter content from nonlinear electrodynamics (NED) supported by gauge-invariant Lagrangians, seeking the feasibility of achieving nonsingular solutions. In this setup, the well-known NED solutions, i.e., the Bardeen and Hayward black holes (BHs) are first examined. Then, some specific dyonic configurations, involving both radial electric and magnetic fields, in the teleparallel gravity framework are analysed. For the special case of a Born-Infeld NED theory, a generalized dyonic Reissner–Nordstrom (RN) solution is obtained in terms of the radial coordinate which exhibits a singular behavior at the origin. Nonetheless, the appearance of a naked singularity is impossible in the adopted Born-Infeld (BI) spacetime. The location and size of horizons depend on the BI parameter, leading to the concept of a hairy BH. However, at infinity it is not distinguishable from a dyonic RNBH characterized only by global charges such as ADM mass, electric and magnetic charges.

Spherically symmetric and static solutions in f(R) gravity coupled with electromagnetic fields

Solutions of field equations in $f(R)$ gravity are found for a spherically symmetric and static spacetime in the Born-Infeld (BI) non-linear electrodynamics. It is found that the models supported in this configuration must have the parametric form $f'(R)|_{r}=m+n r$, with $m,n$ constants, whose value and sign have a strong impact on the solutions, as well as in the form and range of $f(R)$. When $n=0$, $f(R)=m R+m_0$ and the Einstein-BI solution is found. When $m\neq 0$ and $n\neq0$, $f(R)$ is asymptotically equivalent to GR and the Schwarzschild and $f(R)$-Reissner-Nordstr\"om solutions are written in some limits, likewise if $n>0$ and $r\gg1$, $f(R)$ can be found as a series approximation and as a particular case, when $R_S=-\frac{m^2}{3n}$, explicitly $f(R)=m R+2n\sqrt{R}+m_0$. Finally, the solutions, scalar curvature and parametric function $f(r)$ in the non-linear ($m=0$) regime of $f(R)$ are found, and some models for specific values of $m$ and $n$ are plotted.

Fundamental interactions and quantum behavior in unified field theory

The concept of unified field theory is discussed. Two nonlinear field models with world volume type action are considered, namely extremal space-time film model and Born–Infeld nonlinear electrodynamics. The natural appearance of two long-range fundamental interactions, electromagnetism and gravitation, in these field models is discussed. The quantum behavior of the interacting solitons-particles is considered. The concept of quasi-bounding quantization in nonlinear field models is introduced.

Accretion onto Charged Black Holes in Einstein and Massive Theories of Gravity* *Supported by the Higher Education Commission (HEC) under Grant No. 9290/Balochistan/NRPU/R&D/HEC/2017

The accretion process is being investigated onto some important black holes such as Born-Infeld-AdS black hole, non-linear charged black hole solution in AdS space-time and Einstein-Yang-Mills massive gravity in the presence of Born-Infeld nonlinear electrodynamics. We find out the relations of radial velocity, energy density and change of mass for mention black holes and analyze their behavior graphically for different values of equation of state parameters ω. We also examine the relations for critical speed for these black holes. It is observed that for different state parameters different fluids exhibit different evolutions in black holes backgrounds. The energy density of some fluids is negative or positive near the black hole while other fluids become cause to increase or decrease in black hole mass.

Thermodynamics of novel dilatonic BTZ black holes coupled to Born-Infeld electrodynamics

In this work, thermodynamic properties of the three-dimensional charged dilatonic black holes are considered in the presence of Born-Infeld nonlinear electrodynamics. The exact nonlinearly charged black hole solutions to the coupled Einstein-Born-Infeld three-dimensional field equations in the presence of a dilatonic scalar field are constructed. Some new classes of nonlinearly charged dilatonic black hole solutions are distinguished according to different values of the parameters in the theory. The thermodynamics of all of the new Einstein-Born-Infeld-dilaton black holes are studied separately. We show that the thermodynamic quantities satisfy the first law of black hole thermodynamics. Through the canonical ensemble method and noting the black hole heat capacity, we analyze the stability and thermodynamic phase transitions of all of the new Einstein-Born-Infeld-dilaton black holes.

Probing Palatini-type gravity theories through gravitational wave detections via quasinormal modes

The possibility of testing gravity theories with the help of gravitational wave detections has become an interesting arena of recent research. In this paper, we follow this direction by investigating the quasinormal modes (QNMs) of the axial perturbations for charged black holes in the Palatini-type theories of gravity, specifically (1) the Palatini f(R) gravity coupled with Born-Infeld nonlinear electrodynamics and (2) the Eddington-inspired-Born-Infeld gravity (EiBI) coupled with Maxwell electromagnetic fields. The coupled master equations describing perturbations of charged black holes in these theories are obtained with the tetrad formalism. By using the Wentzel-Kramers-Brillouin (WKB) method up to 6th order, we calculate the QNM frequencies of the EiBI charged black holes, the Einstein-Born-Infeld black holes, and the Born-Infeld charged black holes within the Palatini R+alpha R^2 gravity. The QNM spectra of these black holes would deviate from those of the Reissner-Nordström black hole. In addition, we study the QNMs in the eikonal limit and find that for the axial perturbations of the EiBI charged black holes, the link between the eikonal QNMs and the unstable null circular orbit around the black hole is violated.

Overcharging black holes and cosmic censorship in Eddington-inspired Born-Infeld gravity

The Eddington-inspired Born-Infeld (EiBI) gravity is a modification of the theory of general relativity inspired by the nonlinear Born-Infeld electrodynamics. The theory is described by a series of higher curvature terms added to the Einstein-Hilbert action with the parameter $\kappa$. The EiBI gravity has several interesting exact neutral and charged black hole solutions. We study the problem of overcharging extremal black hole solutions of EiBI gravity using a charged test particle to create naked singularity. We show that unlike general relativity, the overcharging could be possible for a charged extremal black hole in EiBI gravity as long as the matter sector is described by usual Maxwell's electrodynamics. Once the matter sector is also modified in accordance to the Born-Infeld prescription with the parameter $b$, the overcharging is not possible as long as the parameters obey the condition $4 \kappa b^2 \leq 1$.

Quasinormal modes of massless scalar fields for charged black holes in the Palatini-type gravity

The scrutiny of black hole perturbations and its application to testing gravity theories have been a very crucial frontier in modern physics. In this paper we study the quasi-normal modes (QNM) of massless scalar perturbations for various charged black holes in the Palatini-type theories of gravity. Specifically, we consider the Palatini $f(R)$ theory coupled with Born-Infeld nonlinear electrodynamics and the Eddington-inspired-Born-Infeld gravity (EiBI) coupled with Maxwell electromagnetic fields. Special attention is paid to Einstein-Born-Infeld black holes, EiBI charged black holes and Born-Infeld charged black holes within $R\pm R^2$ gravity. These charged black holes are shown to be stable and their quasi-normal frequencies, including the frequencies in the eikonal limit, are calculated by using the WKB method up to the 6th order. We compare the results with the Reissner-Nordstr\"om charged black hole and prove that both the changes in the gravity sector and the matter sector of the action alter the QNM spectra.

Thermodynamics of 4-dimensional charged black holes in Brans-Dicke-Born-Infeld gravity theory

In this work, the charged black hole solution to the Brans-Dicke gravity theory in the presence of the nonlinear electrodynamics has been investigated. To simplify the field equations, a suitable conformal transformation has been used which transforms the Brans-Dicke-Born-Infeld Lagrangian to that of Einstein-dilaton theory with new nonlinear electrodynamics field. A new class of 4-dimensional black hole solution has been constructed out as the exact solution to the Brans-Dicke theory in the presence of the Born-Infeld nonlinear electrodynamics. The physical properties of the solutions have been studied. The black hole charge and temperature have been calculated making use of the Gauss’s law and the concept of surface gravity, respectively. Also, the black hole mass and entropy have been obtained from geometrical methods. Through a Smarr-type mass formula as a function of the black hole charge and entropy the black hole temperature and electric potential, as the intensive parameters conjugate to the black hole entropy and charge, have been calculated.

Thermodynamics of nonlinearly charged black holes in the Brans\u2013Dicke modified gravity theory

In this work, the charged black hole solution to the Brans–Dicke gravity theory in the presence of the nonlinear electrodynamics has been investigated. To simplify the field equations, a conformal transformation has been introduced which transforms the Brans–Dicke–Born–Infeld Lagrangian to that of Einstein-dilaton–Born–Infeld theory. A new class of (n+1)-dimensional black hole solution has been constructed out as the exact solution to the Brans–Dicke theory in the presence of the Born–Infeld nonlinear electrodynamics. The physical properties of the solutions have been studied. The black hole charge and temperature have been calculated making use of the Gauss’s law and the concept of surface gravity, respectively. Also, the black hole mass and entropy have been obtained from geometrical methods. Trough a Smarr-type mass formula as a function of the black hole charge and entropy the black hole temperature and electric potential, as the intensive parameters conjugate to the black hole entropy and charge, have been calculated. The consistency of results of the geometrical and thermodynamical approaches confirms the validity of the first law of black hole thermodynamics for this new black hole solution. Finally, making use of the ensemble canonical method, the local stability or phase transition of the new (n+1)-dimensional Brans–Dicke–Born–Infeld black hole solution has been analyzed.

Topologically nontrivial black holes in Lovelock-Born-Infeld gravity

We present the black hole solutions possessing horizon with nonconstant-curvature and additional scalar restrictions on the base manifold in Lovelock gravity coupled to Born-Infeld (BI) nonlinear electrodynamics. The asymptotic and near origin behavior of the metric is presented and we analyze different behaviors of the singularity. We find that, in contrast to the case of the black hole solutions of BI-Lovelock gravity with constant curvature horizon and Maxwell-Lovelock gravity with nonconstant horizon which has only timelike singularities, spacelike, and timelike singularities may exist for BI-Lovelock black holes with nonconstant curvature horizon. By calculating the thermodynamic quantities, we study the effects of nonlinear electrodynamics via the Born-Infeld action. Stability analysis shows that black holes with positive sectional curvature, k, possess an intermediate unstable phase and large and small black holes are stable. We see that while Ricci flat Lovelock-Born-Infeld black holes having exotic horizons are stable in the presence of Maxwell field or either Born Infeld field with large born Infeld parameter beta, unstable phase appears for smaller values of beta, and therefore nonlinearity brings in the instability.

Holographic model for ferromagnetic phase transition in the Lifshitz black hole with the nonlinear electrodynamics

Abstract We numerically investigate the holographic paramagnetism–ferromagnetism phase transition in the 4-dimensional Lifshitz spacetime in the presence of three kinds of typical Born–Infeld-like nonlinear electrodynamics. Concretely, in the probe limit, we thoroughly discuss the effects of the nonlinear parameter b and the dynamical exponent z on the critical temperature, magnetic moment and hysteresis loop. The results show that the exponential form of nonlinear electrodynamics correction makes the critical temperature smaller and the magnetic moment harder to form with the absent external field for a constant nonlinear parameter b comparing it with the logarithmic form of nonlinear electrodynamics and the Born–Infeld nonlinear electrodynamics, especially for the case of larger dynamical exponent z. Moreover, the increase of nonlinear parameter b (for the fixed z) or dynamical exponent z (for the fixed b) will result in extending the period of the external magnetic field. Particularly, the effect of the exponential form of nonlinear electrodynamics on the periodicity of hysteresis loop is more noteworthy.

Reentrant Phase Transitions and Triple Points of Topological AdS Black Holes in Born-Infeld-Massive Gravity

Motivated by recent developments of black hole thermodynamics in de Rham, Gabadadze, and Tolley (dRGT) massive gravity, we study the critical behaviors of topological Anti-de Sitter (AdS) black holes in the presence of Born-Infeld nonlinear electrodynamics. Here the cosmological constant appears as a dynamical pressure of the system and its corresponding conjugate quantity is interpreted as thermodynamic volume. This shows that, besides the Van der Waals-like SBH/LBH phase transitions, the so-called reentrant phase transition (RPT) appears in four-dimensional space-time when the coupling coefficients cim2 of massive potential and Born-Infeld parameter b satisfy some certain conditions. In addition, we also find the triple critical points and the small/intermediate/large black hole phase transitions for d=5.

Holographic paramagnetism–ferromagnetism phase transition with the nonlinear electrodynamics

In the probe limit, we investigate the nonlinear electrodynamical effects of the both exponential form and the logarithmic form on the holographic paramagnetism–ferromagnetism phase transition in the background of a Schwarzschild-AdS black hole spacetime. Moreover, by comparing the exponential form of nonlinear electrodynamics with the logarithmic form of nonlinear electrodynamics and the Born–Infeld nonlinear electrodynamics which has been presented in Ref. [55], we find that the higher nonlinear electrodynamics correction makes the critical temperature smaller and the magnetic moment harder form in the case without external field. Furthermore, the increase of nonlinear parameter b will result in extending the period of the external magnetic field. Especially, the effect of the exponential form of nonlinear electrodynamics on the periodicity of hysteresis loop is more noticeable.

Born–Infeld AdS black holes as heat engines

We study the efficiency of heat engines that perform mechanical work via the pdV terms present in the first law in extended gravitational thermodynamics. We use charged black holes as the working substance, for a particular choice of engine cycle. The context is Einstein gravity with negative cosmological constant and a Born–Infeld nonlinear electrodynamics sector. We compare the results for these ‘holographic’ heat engines to previous results obtained for Einstein–Maxwell black holes, and for the case where there is a Gauss–Bonnet sector.