In this paper, we construct two spherically symmetric thin-shell gravastar models within a BTZ geometry with minimum length. Therefore, in the inner region of the gravastar, we consider an anti-de Sitter metric with minimum length. Thus, for the first model, we introduce the minimum length effect using the probability density of the ground state of the hydrogen atom in two dimensions. For the second gravastar model, we adopt a Lorentzian-type distribution. Also in the outer region, we consider the BTZ black hole metric. So, by examining the inner spacetime, the thin shell, and the outer spacetime, we find that there are different physical characteristics regarding their energy densities and pressures that make the gravastar stable. This effect persists even when the cosmological constant is zero. In addition, we determined the entropy of the gravastar thin shell. Besides, we explore the thermodynamic properties of the BTZ black hole with minimum length in Schwarzschild-type form and also check its stability.

Brazil

M.A. Anacleto

A.T.N. Silva

L. Casarini

Thin-shell Gravastar model in a BTZ geometry with minimum length

We study the influence of Lorentz invariance violation (LIV) background in energy regularization of global structures in <math altimg='si1.svg'><mo stretchy='false'>(</mo><mn>2</mn><mo>,</mo><mn>1</mn><mo stretchy='false'>)</mo></math>&#8211;dimensions. To this end, we consider a model in which the complex scalar and fixed three-vector couple as a high derivative order term. We show that LIV-background does not affect the energy and the equation of motion of neutral global structures. However, we observe that the charged structures are sensitive to LIV-background by presenting signatures in the electric field whose intensity is controlled by the LIV-parameter. Furthermore, the procedure developed leads to first-order solutions with finite energy and a regularized electric field.

M. Paganelly

F.A. Brito

E. Passos

On global vortices in the higher derivative Lorentz-violating scenario

In this paper, we consider the Schwarzschild-Tangherlini black hole to investigate the process of scalar wave scattering by the black hole in a spacetime of <math><mo>(</mo><mi>d</mi><mo>+</mo><mn>1</mn><mo>)</mo></math> dimensions and also with the generalized uncertainty principle (GUP). In this scenario, we analytically determine the phase shift and explore the effect of extra dimensions by calculating the differential scattering and absorption cross-section by applying the partial wave method at low and high-frequency limits. We show at high dimensions that the absorption is not zero as the mass parameter approaches zero.

J.A.V. Campos

E. Maciel

Scattering and absorption by extra-dimensional black holes with GUP

In this study, we consider the four-dimensional Maxwell electrodynamics extended with CPT-even Myers-Pospelov Lorentz-violating dimension-six operators to investigate the associated two-dimensional properties in the context of quantum vacuum fluctuation effects, namely, the Casimir effect. Upon projecting out the 4D theory down to a 2D theory we obtain analogs of these operators leading to a modified dispersion relation in a Lorentz invariance violation (LIV) scalar model equivalent to the electromagnetic theory. By making use of the modified dispersion relation, we derive exact analytic expressions for the Casimir energy and force induced by imposing Dirichlet boundary conditions on the scalar field. In the regime where the LIV parameter becomes very small, we recover known results for the Casimir energy and force plus correction terms due to the LIV.

K.E.L. de Farias

Herondy Mota

Two-dimensional Lorentz-violating Casimir effect

We investigate the effect of noncommutativity and quantum corrections to the temperature and entropy of a BTZ black hole based on a Lorentzian distribution with the generalized uncertainty principle (GUP). To determine the Hawking radiation in the tunneling formalism, we apply the Hamilton-Jacobi method by using the Wentzel-Kramers-Brillouin (WKB) approach. In the present study, we have obtained logarithmic corrections to entropy due to the effect of noncommutativity and GUP. We also address the issue concerning stability of the noncommutative BTZ black hole by investigating its modified specific heat capacity.

B.R. Carvalho

Noncommutative Correction to the Entropy of BTZ Black Hole with GUP

In this paper we have implemented quantum corrections for the Schwarzschild black hole metric using the generalized uncertainty principle (GUP) in order to investigate the scattering process. We mainly compute, at the low energy limit, the differential scattering and absorption cross section by using the partial wave method. We determine the phase shift analytically and verify that these quantities are modified by the GUP. We found that due to the quantum corrections from the GUP the absorption is not zero as the mass parameter goes to zero. A numerical analysis has also been performed for arbitrary frequencies.

Quantum-corrected scattering and absorption of a Schwarzschild black hole with GUP

In this paper we focus on the partial wave method with the aim of exploring the scattering of massless scalar waves due to the noncommutative Schwarzschild black hole via Lorentzian smeared mass distribution. We determine the phase shift analytically in low-frequency limit and we show that the scattering and absorption cross section is modified. Specially, we show that in the low-frequency limit the scattering/absorption cross section has its value decreased when we increase the value of the non-commutativity parameter. In addition, we have confirmed this result by solving the problem numerically for arbitrary frequencies. Such modifications found for the scattering and absorption cross section present similarities with the Reissner-Nordström black hole.

Absorption and scattering of a noncommutative black hole

In this paper we consider the solution of a black hole with a global monopole in <math><mi>f</mi><mo>(</mo><mi>R</mi><mo>)</mo></math> gravity and apply the partial wave approach to compute the differential scattering cross section and absorption cross section. We show that in the low-frequency limit and at small angles the contribution to the dominant term in the scattering/absorption cross section is modified by the presence of the global monopole and the gravity modification. In such limit, the absorption cross section shows to be proportional to the area of the event horizon.

S.J.S. Ferreira

Absorption and scattering of a black hole with a global monopole in ( ) Gravity

We investigate the thermodynamics of a photon gas in an effective field theory model that describes Lorentz violations through dimension-five operators and Horava–Lifshitz theory. We explore the electrodynamics of the model which includes higher order derivatives in the Lagrangian that can modify the dispersion relation for the propagation of the photons. We shall focus on the deformed black body radiation spectrum and modified Stefan–Boltzmann law to address the allowed bounds on the Lorentz-violating parameter.

A. Mohammadi

W.O. Santos

J.R.L. Santos

Lorentz-violating dimension-five operator contribution to the black body radiation

We consider a cosmological setup with inflaton in the presence of a redshift dependent Lorentz-violating time-like background to address the inflationary regime and other phases of the Universe. We also show that the regime of dark energy at large distances (low redshifts) is essentially dominated by the presence of the Lorentz-violating background.