scholarly journals On the quantization of charged black holes with allowance for the cosmological constant

2018 ◽  
Vol 26 (2) ◽  
pp. 3-6
Author(s):  
M. G. Holovko ◽  
V. D. Gladush
Keyword(s):  
Cosmological Constant ◽  
Mass Spectra ◽  
Lagrange Function ◽  
Conformally Flat ◽  
Hamilton Operator ◽  
Charged Black Holes ◽  
Symmetric Configuration ◽  
New Variables ◽  
Mass Functions ◽  
Physical Quantities

The paper considers a spherically symmetric configuration of the gravitational and electromagnetic fields with allowance to the cosmological constant, and its quantization. After dimensional reduction, the original action is transformed to new variables in the R- and T-regions. The exclusion of the non-dynamic degree of freedom from the obtained action leads to an action for the geodesic in the configuration space, which proves to be conformally flat. We use the Gitman–Tyutin formalism for the obtained dynamical system, which Lagrange function is degenerate. After performing a suitable canonical transformation, the constraints found from the Lagrange function are reduced to the canonical form. Herewith the physical part of the Hamilton function vanishes. To construct quantum theory, we introduce additional physical quantities – charge and mass functions. Since Hamilton operator equals zero, it leads to the fact that the desired wave function of the system obeys only the eigenvalue equations for the mass and charge operators. The solution of these equations leads to continuous charge and mass spectra.

scholarly journals The bivariate luminosity and mass functions of the local HRS galaxy sample

2018 ◽  
Vol 617 ◽  
pp. A33 ◽  
Author(s):  
P. Andreani ◽  
A. Boselli ◽  
L. Ciesla ◽  
R. Vio ◽  
L. Cortese ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Far Infrared ◽  
Mass Function ◽  
Stellar Mass ◽  
The Relationship ◽  
Mass Functions ◽  
Physical Quantities

Aims.We discuss the results of the relationships between theK-band and stellar mass, FIR luminosities, star formation rate, and the masses of the dust and gas of nearby galaxies computing the bivariateK-band-luminosity function (BLF) and bivariateK-band-mass function (BMF) of theHerschelReference Survey (HRS), a volume-limited sample with full wavelength coverage.Methods.We derive the BLFs and BMFs from theK-band and stellar mass, FIR luminosities, star formation rate, dust and gas masses cumulative distributions using a copula method, which is outlined in detail. The use of the computed bivariate taking into account the upper limits allows us to derive a more solid statistical ground for the relationship between the observed physical quantities.Results.The analysis shows that the behaviour of the morphological (optically selected) subsamples is quite different. A statistically meaningful result can be obtained over the whole HRS sample only from the relationship between theK-band and the stellar mass, while for the remaining physical quantities (dust and gas masses, far-infrared luminosity, and star formation rate), the analysis is distinct for late-type (LT) and early-type galaxies (ETG). However, the number of ETGs is small to perform a robust statistical analysis, and in most of the case results are discussed only for the LTG subsample. The luminosity and mass functions (LFs, MFs) of LTGs are generally dependent on theK-band and the various dependencies are discussed in detail. We are able to derive the corresponding LFs and MFs and compare them with those computed with other samples. Our statistical analysis allows us to characterise the HRS which, although non-homogeneously selected and partially biased towards low IR luminosities, may be considered as representative of the local LT galaxy population.

Quantum gravity and renormalization

2015 ◽  
Vol 30 (03n04) ◽  
pp. 1540004 ◽  
Author(s):  
Damiano Anselmi
Keyword(s):  
Quantum Gravity ◽  
Point Of View ◽  
Quantum Field ◽  
Conformally Flat ◽  
Field Equations ◽  
Classical Action ◽  
Locally Conformally Flat ◽  
Arbitrary Dimensions ◽  
Conformally Flat Metrics ◽  
Physical Quantities

The properties of quantum gravity are reviewed from the point of view of renormalization. Various attempts to overcome the problem of non-renormalizability are presented, and the reasons why most of them fail for quantum gravity are discussed. Interesting possibilities come from relaxing the locality assumption, which also can inspire the investigation of a largely unexplored sector of quantum field theory. Another possibility is to work with infinitely many independent couplings, and search for physical quantities that only depend on a finite subset of them. In this spirit, it is useful to organize the classical action of quantum gravity, determined by renormalization, in a convenient way. Taking advantage of perturbative local field redefinitions, we write the action as the sum of the Hilbert term, the cosmological term, a peculiar scalar that is important only in higher dimensions, plus invariants constructed with at least three Weyl tensors. We show that the FRLW configurations, and many other locally conformally flat metrics, are exact solutions of the field equations in arbitrary dimensions d>3. If the metric is expanded around such configurations the quadratic part of the action is free of higher-time derivatives. Other well-known metrics, such as those of black holes, are instead affected in nontrivial ways by the classical corrections of quantum origin.

On m-quasi-Einstein spacetimes

2021 ◽  
pp. 2150066
Author(s):  
Absos Ali Shaikh ◽  
Shyamal Kumar Hui ◽  
Akshoy Patra
Keyword(s):  
Vector Field ◽  
Energy Density ◽  
Viscous Fluid ◽  
Cosmological Constant ◽  
Ricci Tensor ◽  
Killing Vector ◽  
Killing Vector Field ◽  
Conformally Flat ◽  
Matter Distribution ◽  
Einstein's Equation

In this paper, we have studied [Formula: see text]-quasi-Einstein spacetimes. Some basic results of such spacetimes are derived. Perfect and viscous fluid [Formula: see text]-quasi-Einstein spacetimes are also studied and the expressions of pressure, cosmological constant and energy density are obtained. We have proved that if the generator [Formula: see text] of an [Formula: see text]-quasi-Einstein spacetime is a Killing vector field, then the spacetime is either conformally flat or of Petrov-type [Formula: see text]. It is also shown that if the function [Formula: see text] of an [Formula: see text]-quasi-Einstein spacetime satisfying Einstein’s equation is harmonic and the matter distribution is perfect fluid, then Segre’ characteristics of the Ricci tensor is [(1,1), 1]. Finally, an example is constructed for the proper existence of such a spacetime.

scholarly journals Quasi-normal modes and stability of Einstein–Born–Infeld black holes in de Sitter space

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Chong Oh Lee ◽  
Jin Young Kim ◽  
Mu-In Park
Keyword(s):  
Black Holes ◽  
Cosmological Constant ◽  
Normal Modes ◽  
Extremal Black Hole ◽  
Wkb Method ◽  
De Sitter ◽  
Charged Black Holes ◽  
Resonance Modes ◽  
Metric Functions ◽  
The Stability

Abstract We study gravitational perturbations of electrically charged black holes in (3+1)-dimensional Einstein–Born–Infeld gravity with a positive cosmological constant. For the axial perturbations, we obtain a set of decoupled Schrödinger-type equations, whose formal expressions, in terms of metric functions, are the same as those without cosmological constant, corresponding to the Regge–Wheeler equation in the proper limit. We compute the quasi-normal modes (QNMs) of the decoupled perturbations using the Schutz–Iyer–Will’s WKB method. We discuss the stability of the charged black holes by investigating the dependence of quasi-normal frequencies on the parameters of the theory, correcting some errors in the literature. It is found that all the axial perturbations are stable for the cases where the WKB method applies. There are cases where the conventional WKB method does not apply, like the three-turning-points problem, so that a more generalized formalism is necessary for studying their QNMs and stabilities. We find that, for the degenerate horizons with the “point-like” horizons at the origin, the QNMs are quite long-lived, close to the quasi-resonance modes, in addition to the “frozen” QNMs for the Nariai-type horizons and the usual (short-lived) QNMs for the extremal black hole horizons. This is a genuine effect of the branch which does not have the general relativity limit. We also study the exact solution near the (charged) Nariai limit and find good agreements even far beyond the limit for the imaginary frequency parts.

scholarly journals The Importance of Scalar Fields as Extradimensional Metric Components in Kaluza-Klein Models

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
P. H. R. S. Moraes ◽  
R. A. C. Correa
Keyword(s):  
Cosmological Constant ◽  
Extra Dimension ◽  
Scalar Fields ◽  
Observable Universe ◽  
Standard Cosmology ◽  
The Creation ◽  
Creation Of Matter ◽  
Physical Quantities ◽  
Kaluza Klein ◽  
Hierarchy Problems

Extradimensional models are achieving their highest popularity nowadays, among other reasons, because they can plausible explain some standard cosmology issues, such as the cosmological constant and hierarchy problems. In extradimensional models, we can infer that the four-dimensional matter rises as a geometric manifestation of the extra coordinate. In this way, although we still cannot see the extra dimension, we can relate it to physical quantities that are able to exert such a mechanism of matter induction in the observable universe. In this work we propose that scalar fields are those physical quantities. The models here presented are purely geometrical no matter the fact that Lagrangian is assumed and even the scalar fields are contained in the extradimensional metric. The results are capable of describing different observable cosmic features and yield an alternative to ultimately understand the extra dimension and the mechanism in which it is responsible for the creation of matter in the observable universe.

scholarly journals ON THE STRUCTURE OF THE CONFIGURATION SPACE OF CHARGED BLACK HOLES

2021 ◽  
Vol 34 ◽  
pp. 11-17
Author(s):  
V.D. Gladush
Keyword(s):  
Black Holes ◽  
Electromagnetic Fields ◽  
Configuration Space ◽  
Conservation Law ◽  
Integrability Condition ◽  
Free Particle ◽  
Hamiltonian Constraint ◽  
Spherically Symmetric ◽  
Charged Black Holes ◽  
Symmetric Configuration

Some properties of the configuration space (CS) of charged black holes (BH) we are considered. A reduced action for the spherically symmetric configuration of the gravitational and electromagnetic fields is constructed. We restrict ourselves to considering of T-region, where the studied fields have a dynamic meaning. Using the Hamiltonian constraint, we exclude the nondynamic degree of freedom. This leads to the action of the system in the CS with the corresponding supermetric. It turns out that the CS is flat, and its metric admits a twoparametric group of motions. This group generates conservation laws for the geodesic equations. The first law is the charge conservation law, and second is the mass conservation law (the mass function). Using the Hamiltonian constraint, they allow one to find momenta as a function of the field variables andcalculate the action as a function of the conserved quantities and field variables in CS. We emphasize that to find this  action, we use only the integrability condition for a differential form. The quantization of the system is reduced to the  uantization of a free particle in a three-dimensional pseudo-Euclidean space. The natural measure corresponding to the CS metric is used to construct the Hermitian DeWitt and mass operators. Based on the self-consistent solution of quantum  DeWitt equations and equations for the eigenvalues of the mass and charge operators, the wave function for the spherically  symmetric configuration of the gravitational and electromagnetic fields in the T- region is constructed. As a result, we get a model of charged BH with continuous mass and charge spectra.

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