arXiv subjects

Daniel Martínez-Carbajal

Publications and source records attributed to Daniel Martínez-Carbajal.

8 recordsLinked to original sources

arXiv2025

Noncommutative AdS black hole and the IR holographic superconductor

We construct a noncommutative (NC) AdS$_4$-charged black hole with a planar horizon topology. The NC effects of this geometry are captured by a Gaussian distribution of black hole mass codified in a fluid-like energy-momentum tensor. A natural bound in radial coordinate is established, below which the scalar curvature changes its sign and defines a NC cutoff that embeds the point singularity. We study in detail the thermodynamic structure of this scenario, finding a well-defined black hole mass and an analytic criterion for its stability. Focusing on the AdS$_2$ structure near the horizon, we find a novel effective curvature radius with dependency on the NC cutoff. These results motivate us to explore the holographic superconducting system in terms of the nearness from the cutoff. The behavior of the magnetic field in the deep IR geometry is studied and we found semi-analytical novel expressions for the upper critical magnetic fields of a dual type-II superconductor in the canonical and grand canonical ensembles. The condensation in the form of hair is studied in terms of the bound states of the associated Schrödinger potential of the scalar field, interpreted as the dual to the density of Cooper pairs. The NC effects increase the hair formation due to a steeper AdS$_2$ throat comparable to the commutative case. Finally, we obtain the effective IR scalar field equation on the near-horizon and near-extremal NC Schwarzschild AdS$_2$ geometry and confirm that NC effects promote bound states that the commutative version forbids.

hep-th↗

arXiv2023

Electric traversable wormhole supported by a charged scalar field

Solving the Einstein-Klein-Gordon-Maxwell system, we construct and analyze the properties of an electrically charged wormhole, formed from a complex, massive scalar field, with self-interaction, and endowed with an electric charge. The scalar field is minimally coupled to the gravitational and the Maxwell field. Covering regions of the value of the different parameters of such wormhole, we present the dependence of the form of the solution with respect to the value of the different parameters, emphasising the role played by the charge in the configurations; we focus on the region for large values of the self-interaction parameter and found a generic behavior of the scalar field, which in turn allows us to determine explicit analytic expressions for the fields, the metric function and the global quantities such as the Komar mass and the particle number. The motion of charges in these spacetimes is also reported.

gr-qc↗

arXiv2023

Born-Infeld boson stars

We study the Einstein-Klein-Gordon system coupled to the Born-Infeld electrodynamics. We explore the solution space of a static spherically symmetric, complex scalar field minimally coupled to both gravitational and electromagnetic fields. The resulting asymptotically flat solutions resemble the known charged boson stars in Maxwell electrodynamics. The behaviour of such configurations as a function of the Born-Infeld parameter $b$ and the scalar field charge parameter $q$ has been analyzed. Given $b$, a critical value for $q$ exists beyond which no static solutions exist, we find that the value of this critical charge increases with respect to the Maxwell case ($b\to\infty$) as $b$ decreases. We also found that Born-Infeld boson stars have lower mass for any finite value of the Born-Infeld parameter and that their compactness is lower than Maxwell's counterparts.

gr-qc↗

arXiv2023

Implications of Seiberg-Witten map on type-I superconductors

We incorporate the Seiberg-Witten map of noncommutative theory in the classical London theory of type-I superconductivity when an external magnetic field is applied. After defining the noncommutative Maxwell potentials, we derive the London equation for the supercurrent as a function of the noncommutative parameter, up to second order in gauge fields expansion. Keeping track of the effects of noncommutative gauge fields, we argue that noncommutative magnetic field effects can be cast in the permeability of the superconductor as an emergent property of the material, measurable in possible not-so-far ultra-high-energy experimental setups. Another consequence of the Seiberg-Witten map is the London penetration length that acquires corrections in the expansion. Also, we show that the flux quantization remains consistent relative to the commutative case. Our effective magnetic permeability and London penetration length reduce to the standard ones in the commutative limit.

hep-th↗

arXiv2020

Shadow of a noncommutative inspired Einstein-Euler-Heisenberg black hole

Using a noncommutative inspired Einstein-Euler-Heisenberg black hole, we analyse the associated graviton and light rings that together with the event horizon, provide the necessary components to build its shadow. An analysis of the angular radius of the noncommutative inspired Einstein-Euler-Heisenberg black hole shows that for observers located in its vicinity, it becomes smaller when compared with the commutative case; this effect is more noticeable as noncommutativity increases. The existence of marginally stable bound orbits and the critical angle for the escaping of photons of a noncommutative inspired Einstein-Euler-Heisenberg star is also discussed.

gr-qc↗

arXiv2019

A Kähler Compatible Moyal Deformation of the First Heavenly Equation

We construct a noncommutative Kähler manifold based on a non-linear perturbations of Moyal integrable deformations of $D=4$ self-dual gravity. The deformed Kähler manifold preserves all the properties of the commutative one, and we obtain the associated noncommutative Kähler potential using the Moyal deformed gravity approach. We apply this construction to the Atiyah-Hitchin metric and its Kähler potential, which is useful in the description of interactions among magnetic monopoles at low energies.

math-ph↗

arXiv2016

Noncommutative Dirac quantization condition using the Seiberg-Witten map

We investigate the validity of the Dirac quantization condition (DQC) for magnetic monopoles in noncommutative space-time. We use an approach based on an extension of the method introduced by Wu and Yang; the effects of noncommutativity are analyzed using the Seiberg-Witten map and the corresponding deformed Maxwell's equations are discussed. By means of a perturbation expansion in the noncommutativity parameter $θ$, we show first that the DQC remains unmodified up to the first and second order. This result is then generalized to all orders in the expansion parameter for a class of noncommutative electric currents induced by the Seiberg-Witten map; these currents reduce to the Dirac delta function in the commutative limit.

hep-th↗

arXiv2014

Test Particle Motion in the Born-Infeld Black Hole

In this work we review the classification of geodesics of massive test particles in the gravitational background of the black hole solutions of Einstein-Born-Infeld spacetime. Even though some features are quite similar to those of Reissner-Nordström spacetime there are also important differences, particularly those related to the effective potential governing the geodesic motion. Explicit solutions involving Weierstrass functions are given for a pair of specific scenarios.

gr-qc↗