Born Infeld Research Articles

Quintessence anisotropic stellar models in quadratic and Born–Infeld modified teleparallel Rastall gravity

This study aims to discuss anisotropic solutions that are spherically symmetric in the quintessence field, which describe compact stellar objects in the modified Rastall teleparallel theory of gravity. To achieve this goal, the Krori and Barua arrangement for spherically symmetric components of the line element is incorporated. We explore the field equations by selecting appropriate off-diagonal tetrad fields. Born–Infeld function of torsion f(T)=βλT+1−1 and power law form h(T) = δTn are used. The Born–Infeld gravity was the first modified teleparallel gravity to discuss inflation. We use the linear equation of state pr = ξρ to separate the quintessence density. After obtaining the field equations, we investigate different physical parameters that demonstrate the stability and physical acceptability of the stellar models. We use observational data, such as the mass and radius of the compact star candidates PSRJ 1416-2230, Cen X-3, & 4U 1820-30, to ensure the physical plausibility of our findings.

Mixed-state entanglement for AdS Born-Infeld theory

We study the mixed-state entanglement for AdS Born-Infeld (BI) theory. We calculate the mixed-state entanglement and investigate the relationship between it and the system parameters. We find that the holographic entanglement entropy (HEE) and mutual information (MI) exhibit monotonically increasing and decreasing behavior with BI factor b. However, the entanglement wedge cross-section (EWCS) exhibits a very rich set of phenomena about system parameters. EWCS always increases with b when b is small and then monotonically decreases with b. These behaviors suggest that increasing the BI factor, which is essentially enhancing the coupling between the background geometry and the transport properties can always enhance the EWCS. The coupling between the entanglement and the transport behaviors has also been studied in condensed matter theories and is important to construct a stable quantum circuit. We also provide analytical understanding of the above phenomenon. Furthermore, we have tested two additional BI-like models and find the universality of these results, suggesting the crucial role of the BI term in governing the interplay between nonlinear electromagnetic effects and entanglement.

Exact multicentered static point charge source distributions in the Born–Infeld theory of nonlinear electromagnetism and presence of electric and magnetic currents

Exact multicentered solutions to the governing equations of the Born–Infeld nonlinear theory of electrodynamics describing distributions of electric, magnetic, and dyonic point charge sources are constructed explicitly for the first time. The method of construction may effectively be adapted to obtain such solutions in generalized theories as well. As a consequence, the solutions unveil that, in order to achieve a balance between such multicentered electric or magnetic point charge distribution in equilibrium, a static magnetic or electric current must be present, resulting in non-conservativeness of the induced electric or magnetic intensity field, respectively and universally. Moreover, it is also shown that the methods of construction and conclusions drawn in the multicentered situation may be extended to obtain exact solutions and similar conclusions, explicitly, in the situation of continuously distributed charge source problems.

Conformally invariant nonlinear electrodynamic actions and its non-abelian extensions

In this work, formal theoretical aspects concerning conformally invariant functional actions of electrodynamics are presented and discussed. In particular, the origin of the conformal and duality invariant Lagrangians of [I. Bandos et al., J. High Energy Phys. 10 (2021) 031; I. Bandos, K. Lechner, D. Sorokin and P. Townsend, Phys. Rev. D 102 (2020) 121703] (e.g. ModMax) and also Born–Infeld types are analyzed being its non-abelian counterpart presented and discussed explicitly for the gauge group SU(2). Implications on the properties of the gravitational field are briefly discussed by means of new symmetries of the field equations.

Tree and 1-loop fundamental BCJ relations from soft theorems

We provide a new derivation of the fundamental BCJ relation among double-color-ordered tree amplitudes of bi-adjoint scalar theory, based on the leading soft theorem for external scalars. Then, we generalize the fundamental BCJ relation to 1-loop Feynman integrands. We also use the fundamental BCJ relation to understand Adler’s zero for tree amplitudes of the nonlinear sigma model and Born–Infeld theory.

Multiple Solutions for a Nonhomogeneous Schrödinger–Born–Infeld System

Multiple Solutions for a Nonhomogeneous Schrödinger–Born–Infeld System

Towards precise constraints in modified gravity: bounds on alternative coupling gravity using white dwarf mass-radius measurements

Tests have to be performed to rule out proposals for gravity modification. We propose a new idea for constraining alternative theories of gravity using temperature-dependent white dwarf (WD) mass-radius (MR) observational data. We have shown that several alternatives to general relativity (GR), which modified GR only within matter, might be reduced to the well-known Poisson equation similar to that of Eddington-inspired Born Infeld (EiBI) and Minimal Exponential Measure (MEMe) gravity. Retaining EiBI notation, we constrain the value of the coupling constant, kappa , using a high-precision model-independent measurement of WD MR observations. We have demonstrated that the WD model should include detailed physics to achieve good precision. The model should include their temperature and evolutionary aspects, which may be computationally expensive. To overcome this issue, we construct a semi-analytical surrogate model based on Mestel’s model, calibrated with tabulated, detailed realistic models, to correct the zero-temperature radius. We have shown that the best-fit value of kappa depends on the WD model, with the ’thick’ envelope models more consistent in describing data. The tightest bound obtained from the most precise MR measurement, QS Vir, with -0.19lesssim kappa lesssim 0.22 in 10^3 m^5kg^{-1} s^{-2} for 2sigma (sim 95%) credibility. Overall, we assert that the recent precise WD MR measurements, combined with our current understanding of WD structure, are insufficient to see the deviation from the one predicted by GR. Both more precise observation data and detailed WD modelling are required to rule out gravity modification.

Born–Infeld corrections to holographic transport coefficients with spatially modulated chemical potential

In this work, we have analytically computed the holographic transport coefficients for (2+1)-dimensional strongly coupled field theories, placed in a spatially modulated chemical potential along the x-direction, in the presence of Born–Infeld electrodynamics. We have obtained these coefficients in terms of the black hole horizon data only. We have observed that the Born–Infeld parameter affects these coefficients in a non-trivial way. We have, then, used these results to further study a holographic model for ultra-clean graphene near Dirac point. This is a two current model with an inhomogeneous holographic lattice.

Probing modified plasma waves in non-linear electrodynamics

Properties of modified plasma waves in non-linear electrodynamics are investigated. We consider a cold, uniform, collisionless, and magnetized plasma model. Initially, we also assume small amplitude waves and the non-relativistic approximation. For electrostatic waves, we obtain a modified Trivelpiece–Gould dispersion relation with a suitable change in the plasma frequency and analyze the stability of modes. Furthermore, electromagnetic waves related to the generalized Appleton–Hartree equation are established. In this case, we discuss modifications in circularly polarized waves and ordinary and extraordinary modes. After that, we apply our results to particular cases of low-energy quantum electrodynamics and a generalized Born–Infeld model. The correspondent dispersion relations and effects on the propagation regions are determined. Finally, we include the relativistic and large amplitude effects for circularly polarized waves. We obtain the dispersion relation within effective non-linear electrodynamics and examine the behavior of the refractive index when the frequency of the propagating wave converges to the plasma frequency.

Novel charged black hole solutions of Born–Infeld type: General properties, Smarr formula and Quasinormal frequencies

We investigate two novel models of charged black holes in the framework of non-linear electrodynamics of Born–Infeld type. In particular, starting from two concrete Lagrangian densities, the corresponding metric potentials, the electric field, the Smarr formula and finally, the (scalar) quasinormal modes are computed for each model. Our findings show that although the models look very similar, their quasinormal spectra are characterized by certain differences.

Observational appearances of magnetically charged black holes in Born–Infeld electrodynamics

In this paper, we investigate the observational appearances of magnetically charged black holes in Born–Infeld (BI) electrodynamics. We examine the effects of the magnetic charge and the BI parameter on the geodesics with different impact parameters. Using the backward ray tracing method, we investigate how spherically symmetric accretions interact with black hole shadows and photon spheres. The shadows of infalling accretion are darker than that of static ones. Moreover, the radius of the photon sphere is an intrinsic property of the spacetime independent of accretions. We then study how the thin disk models affect the black hole shadows. After obtaining the transfer functions, we divide photons emitted from the thin disk into three categories: direct emission, lens ring, and photon ring. Applying three emission models, we find that the width of the shadow is dominated by the direct emission, the photon ring and the lens ring can hardly be identified by changing the emission models.

Bosonic quantum dynamics in Eddington-inspired Born–Infeld gravity global monopole spacetime

We have investigated the relativistic quantum dynamics of a bosonic field in Born–Infeld spacetime with a topological charge by characterizing the global monopole. Firstly, we have analyzed a free bosonic field, by definition, is free in this non-trivial geometry. Due to the effects of the geometry, in fact, the spin-0 boson is confined, of which it is possible to obtain solutions of bound states. Then, in order to generalize the system, we introduce the interaction of the relativistic oscillator and, analytically, we obtain the relativistic energy profile of the system.

Born–Infeld-f(R) gravity with de Sitter solutions

In this study, we consider Born–Infeld-[Formula: see text] gravity in which the [Formula: see text] term enters directly into the square root in the Palatini formulation. We briefly analyzed this model for an explicit [Formula: see text] function which includes positive and negative powers of the curvature scalar. We also show that both the ordinary Born–Infeld-[Formula: see text] and this modification reduce to the same gravitational action form under the conformal approach. Then, we consider the existence of a maximally symmetric vacuum solution for the gravitational field equations and find the de Sitter solution for this modified model.

Gravitational duality, Palatini variation and boundary terms: a synopsis

We consider f(R) gravity and Born–Infeld–Einstein (BIE) gravity in formulations where the metric and connection are treated independently and integrate out the metric to find the corresponding models solely in terms of the connection, the archetypical treatment being that of Eddington–Schrödinger (ES) duality between cosmological Einstein and Eddington theories. For dimensions , we find that this requires f(R) to have a specific form which makes the model Weyl invariant, and that its Eddington reduction is then equivalent to that of BIE with certain parameters. For D = 2 dimensions, where ES duality is not applicable, we find that both models are Weyl invariant and equivalent to a first order formulation of the bosonic string. We also discuss the form of the boundary terms needed for the variational principle to be well defined on manifolds with non-null boundaries. This requires a modification of the Gibbons–Hawking–York (GHY) boundary term for gravity. This modification also means that the dualities between metric and connection formulations are consistent and include the boundary terms.

On Einstein–Born–Infeld conformally invariant theory

A new Weyl Born Infeld model is presented. It takes as basis the formalism for the mathematical description of conformal gravity based on the local twistor geometry from Merkulov (Class Quantum Gravity 1:349–354, 1984). As in the pure Maxwell case, the electromagnetic field can be naturally incorporated into this scheme by a modification of the local twistor parallel transport law. The dynamical equations of the linear case, namely the Bach equations for gravity and the Maxwell equations for the electromagnetic field, can not be obtained by varying a single quantity-the modified twistor connection, unless a geometric condition on a particular function of the invariants is imposed. When that condition is met, the Weyl–Maxwel gravity system are contained in the obtained set. The invariance under standard dualities and other generalized maps are briefly discussed.

Deflection in higher dimensional spacetime and asymptotically non-flat spacetimes

Using a perturbative technique, in this work we study the deflection of null and timelike signals in the extended Einstein–Maxwell spacetime, the Born–Infeld gravity and the charged Ellis–Bronnikov (CEB) spacetime in the weak field limit. The deflection angles are found to take a (quasi-)series form of the impact parameter, and automatically takes into account the finite distance effect of the source and observer. The method is also applied to find the deflections in CEB spacetime with arbitrary dimension. It’s shown that to the leading non-trivial order, the deflection in some n-dimensional spacetimes is of the order . We then extended the method to spacetimes that are asymptotically non-flat and studied the deflection in a nonlinear electrodynamical scalar theory. The deflection angle in such asymptotically non-flat spacetimes at the trivial order is found to be not π anymore. In all these cases, the perturbative deflection angles are shown to agree with numerical results extremely well. The effects of some nontrivial spacetime parameters as well as the signal velocity on the deflection angles are analyzed.

Phenomenology of strong interactions: towards an effective theory for low energy QCD

In this paper, we develop models applicable to phenomenological particle physics by using the string analogy of particles. These theories can be used to investigate the phenomenology of confinement, deconfinement, chiral condensate, QGP phase transitions, and even the evolution of the early universe. Other confining properties such as scalar glueball mass, gluon mass, glueball-meson mixing states, QCD vacuum, and color superconductivity can also be investigated in these model frameworks. We use one of the models to describe the phenomenon of color confinement among glueballs at the end of the paper. The models are built based on the Dirac–Born–Infeld (DBI) action modified for open strings with their endpoints on a Dp-brane or brane–anti-brane at a tachyonic vacuum.

Cosmological implications of Born–Infeld-f(R) gravity

In this paper, a modified Born–Infeld gravitation theory with an [Formula: see text] function being added to the determinant action is analyzed from a cosmological viewpoint. The corresponding accelerating dynamics are studied in a simplified conformal approach without matter. Three different structures for the auxiliary metric function are analyzed, with the aim to establish a deeper understanding of the role of this function in cosmology. After performing the analysis, it is seen that by modifying the auxiliary metric function, a Big Rip singularity or either a Little Rip dark energy model may arise.

On affine geometrical structure, generalized of Born–Infeld models and Eddington’s world conjectures

In this work, we give a detailed description and discussion of the dynamic gravitational equations of the model with Lagrangian of the type [Formula: see text] as proposed by Eddington time ago but with [Formula: see text] being a non-Riemannian generalization of the Ricci tensor with the end to find the geometrical origin of the Eddington and Weyl conjectures concerning Lagrangian densities (generalized volume) and natural gauge. The Ricci tensor in our case is particularly based on an affine geometry with a generalized compatibility condition previously proposed in [B. McInnes, On the geometrical interpretation of ‘non-symmetric’ space-time field structures, Class. Quantum Grav. 1 (1984) 105–113; D. J. Cirilo-Lombardo, Non-Riemannian geometry, Born–Infeld models and trace-free gravitational equations, J. High Energy Astrophys. 16 (2017) 1–14]. Specifically, we show that: (i) the geometric action can be taken to a BI-type form considering a totally antisymmetric torsion field, (ii) Weyl’s proposal considering a universal gauge linked to a cosmological constant [Formula: see text] appears in the model naturally due to the proposed affine geometry, (iii) the Eddington conjecture that establishes a relationship between metric and curvature or fundamental tensor with constant of proportionality [Formula: see text] (natural gauge) is geometrically verified in the model with generalized affine geometry.

Study of anisotropic universe in presence of DBI-essence, phantom and tachyonic fields

This work is devoted to study the roles of Dirac–Born–Infeld (DBI)-essence, scalar field, phantom field, normal tachyonic field and phantom tachyonic field models driving the present expansion of the universe with acceleration in anisotropic background. To understand the different phase of the Bianchi I universe, the statefinder parameters and deceleration parameter are investigated diagrammatically. The radiation era to [Formula: see text]CDM model has been generated. The anisotropic parameters are analyzed during the evolution of the universe. It has been shown that DBI-essence, scalar field, phantom field, normal tachyonic field and phantom tachyonic field play an active role of dark energy which causes the acceleration of the anisotropic universe.