scholarly journals Black holes with a nonconstant kinetic term in degenerate higher-order scalar tensor theories

2020 ◽  
Vol 101 (4) ◽  
Author(s):  
Masato Minamitsuji ◽  
James Edholm
Keyword(s):  
Black Holes ◽  
Higher Order ◽  
Kinetic Term

scholarly journals Magnetic black holes with higher-order curvature and gauge corrections in even dimensions

2010 ◽  
Vol 2010 (8) ◽  
Author(s):  
Hideki Maeda ◽  
Mokhtar Hassaïne ◽  
Cristián Martínez
Keyword(s):  
Black Holes ◽  
Higher Order

Normal-mode frequencies of Reissner–Nordström black holes

1993 ◽  
Vol 442 (1915) ◽  
pp. 427-436 ◽  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Numerical Integration ◽  
Normal Mode ◽  
Characteristic Frequency ◽  
Continued Fraction ◽  
Higher Order ◽  
Coordinate Plane ◽  
Phase Amplitude

The normal-mode frequencies of a Reissner–Nordström black hole are determined from a phase-amplitude formula, using numerical integration in the complex coordinate plane. The results obtained are numerically very accurate, extending previous higher-order WKB results of Kokkotas and Schutz as well as the continued fraction results of Leaver. The change in the characteristic frequency of each mode as the charge of the black hole increases is also discussed.

Thermodynamics of black holes with higher order corrected entropy

2019 ◽  
Vol 97 (7) ◽  
pp. 742-751 ◽  
Author(s):  
M. Umair Shahzad ◽  
Abdul Jawad
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Higher Order ◽  
De Sitter ◽  
Free Energies ◽  
Corrected Entropy ◽  
The Stability ◽  
Canonical Ensembles ◽  
Thermodynamical Behavior ◽  
Correction Terms

For analyzing the thermodynamical behavior of two well-known black holes, such as Reissner–Nordström – anti-de Sitter (RN-AdS) black hole with global monopole and f(R) black hole, we consider the higher order logarithmic corrected entropy. We develop various thermodynamical properties, such as entropy, specific heat, pressure, and Gibbs and Helmhotz free energies for both black holes in the presence of corrected entropy. A versatile study on the stability of black holes is made by using various frameworks, such as the ratio of heat capacities (γ), grand canonical and canonical ensembles, and phase transition in view of higher order logarithmic corrected entropy. It is observed that both black holes exhibit more stability (locally as well as globally) for growing values of cosmological constant and higher order correction terms.

scholarly journals Primordial black holes formation in the inflationary model with field-dependent kinetic term for quartic and natural potentials

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
Milad Solbi ◽  
Kayoomars Karami
Keyword(s):  
Black Holes ◽  
Mass Scale ◽  
Kinetic Term ◽  
Density Parameter ◽  
Primordial Black Holes ◽  
Inflationary Model ◽  
Field Dependent ◽  
Power Law Function ◽  
Infrared Limit ◽  
The Universe

AbstractWithin the framework of inflationary model with field-dependent kinetic term for quartic and natural potentials, we investigate generation of the primordial black holes (PBHs) and induced gravitational waves (GWs). In this setup, we consider a kinetic function as $$G(\phi )=g_I(\phi )\big (1+g_{II}(\phi )\big )$$ G ( ϕ ) = g I ( ϕ ) ( 1 + g II ( ϕ ) ) and show that in the presence of first term $$g_I(\phi )$$ g I ( ϕ ) both quartic and natural potentials, in contrast to the standard model of inflation, can be consistent, with the 68% CL of Planck observations. Besides, the second term $$g_{II}(\phi )$$ g II ( ϕ ) can cause a significant enhancement in the primordial curvature perturbations at the small scales which results the PBHs formation. For the both potentials, we obtain an enhancement in the scalar power spectrum at the scales $$k\sim 10^{12}~{\mathrm{Mpc}}^{-1}$$ k ∼ 10 12 Mpc - 1 , $$10^{8}~{\mathrm{Mpc}}^{-1}$$ 10 8 Mpc - 1 , and $$10^{5}~{\mathrm{Mpc}}^{-1}$$ 10 5 Mpc - 1 , which causes PBHs production in mass scales around $$10^{-13}M_{\odot }$$ 10 - 13 M ⊙ , $$10^{-5}M_{\odot }$$ 10 - 5 M ⊙ , and $$10 M_{\odot }$$ 10 M ⊙ , respectively. Observational constraints confirm that PBHs with a mass scale of $$10^{-13}M_{\odot }$$ 10 - 13 M ⊙ can constitute the total of dark matter in the universe. Furthermore, we estimate the energy density parameter of induced GWs which can be examined by the observation. Also we conclude that it can be parametrized as a power-law function $$\Omega _{\mathrm{GW}}\sim (f/f_c)^n$$ Ω GW ∼ ( f / f c ) n , where the power index equals $$n=3-2/\ln (f_c/f)$$ n = 3 - 2 / ln ( f c / f ) in the infrared limit $$f\ll f_{c}$$ f ≪ f c .

scholarly journals Thermodynamics of the Schwarzschild and Reissner–Nordström black holes under higher-order generalized uncertainty principle

2021 ◽  
Vol 136 (9) ◽  
Author(s):  
S. Hassanabadi ◽  
J. Kříž ◽  
W. S. Chung ◽  
B. C. Lütfüoğlu ◽  
E. Maghsoodi ◽  
...  
Keyword(s):  
Black Holes ◽  
Uncertainty Principle ◽  
Generalized Uncertainty Principle ◽  
Higher Order

scholarly journals Higher-order Skyrme hair of black holes

2018 ◽  
Vol 2018 (5) ◽  
Author(s):  
Sven Bjarke Gudnason ◽  
Muneto Nitta
Keyword(s):  
Black Holes ◽  
Higher Order
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