scholarly journals Role of electric charge in shaping equilibrium configurations of fluid tori encircling black holes

2011 ◽  
Vol 84 (8) ◽  
Author(s):  
Jiří Kovář ◽  
Petr Slaný ◽  
Zdeněk Stuchlík ◽  
Vladimír Karas ◽  
Claudio Cremaschini ◽  
...  
Keyword(s):  
Black Holes ◽  
Electric Charge ◽  
Equilibrium Configurations

scholarly journals Temperature oscillations of a gas moving close to circular geodesic in Reissner–Nordström spacetime

2019 ◽  
Vol 28 (04) ◽  
pp. 1950059 ◽  
Author(s):  
Leandro Cesar Mehret ◽  
Gilberto Medeiros Kremer
Keyword(s):  
Black Holes ◽  
Electric Charge ◽  
Periodic Oscillation ◽  
Compact Stars ◽  
Quark Stars ◽  
Temperature Oscillations ◽  
Inverse Effect ◽  
Low Mass ◽  
X Ray Binaries

The objective of this work is to analyze the temperature oscillations that occur in a gas in a circular motion under the action of a Reissner–Nordström gravitational field, verifying the effect of the charge term of the metric on the oscillations. The expression for temperature oscillations follows from Tolman’s law written in Fermi normal coordinates for a comoving observer. The motion of the gas is close to geodesic so the equation of geodesic deviation was used to obtain the expression for temperature oscillations. Then these oscillations are calculated for some compact stars, quark stars, black holes and white dwarfs, using values of electric charge and mass from models found in the literature. Comparing the various models analyzed, it is possible to verify that the role of the charge is the opposite of the mass. While the increase of the mass produces a reduction in the frequencies, amplitude and, in the ratio between the frequencies, the increase of the electric charge produces the inverse effect. In addition, it is shown that if the electric charge is proportional to the mass, the ratio between the frequencies does not depend on the mass, but only on the proportionality factor between charge and mass. The ratios between the frequencies for all the models analyzed (except for supermassive black holes in the extreme limit situations) are close to the [Formula: see text] ratio for twin peak quasi-periodic oscillation (QPO) frequencies, observed in many galactic black holes and neutron star sources in low-mass X-ray binaries.

scholarly journals Global monopole metric in 2 + 1 dimensions

2019 ◽  
Vol 16 (01) ◽  
pp. 1950006
Author(s):  
S. Habib Mazharimousavi ◽  
M. Halilsoy
Keyword(s):  
Exact Solution ◽  
Cosmological Constant ◽  
Electric Charge ◽  
Radial Distance ◽  
Series Solutions ◽  
Global Monopole ◽  
Negative Cosmological Constant ◽  
Consistent Manner ◽  
Positive Integers

In order to obtain the geometry of a global monopole without cosmological constant and electric charge in [Formula: see text] dimensions, we make use of the broken [Formula: see text] symmetry. In the absence of an exact solution, we determine the series solutions for both the metric and monopole functions in a consistent manner that satisfies all equations in appropriate powers. The new expansion elements are of the form [Formula: see text] for the radial distance [Formula: see text] and positive integers [Formula: see text] and [Formula: see text] constrained by [Formula: see text]. To the lowest order of expansion, we find that in analogy with the negative cosmological constant the geometry of the global monopole acts repulsively, i.e. in the absence of a cosmological constant the global monopole plays at large distances the role of a negative cosmological constant.

The role of electric charge in microdroplets impacting on conducting surfaces

2010 ◽  
Vol 22 (5) ◽  
pp. 051703 ◽  
Author(s):  
Weiwei Deng ◽  
Alessandro Gomez
Keyword(s):  
Electric Charge

Inconsistency of conservation laws for the baryon number and electric charge with the conception of black holes

2011 ◽  
Vol 56 (7) ◽  
pp. 359-361 ◽  
Author(s):  
S. S. Gershtein ◽  
A. A. Logunov ◽  
M. A. Mestvirishvili
Keyword(s):  
Black Holes ◽  
Conservation Laws ◽  
Electric Charge ◽  
Baryon Number

scholarly journals The Enigma of the Muon and Tau Solved by Emergent Quantum Mechanics?

2019 ◽  
Vol 9 (7) ◽  
pp. 1471
Author(s):  
Theo van Holten
Keyword(s):  
Quantum Mechanics ◽  
Droplet Model ◽  
Matter Waves ◽  
Equilibrium Configurations ◽  
Self Consistent ◽  
Usual Quantum ◽  
Electron Models ◽  
Charged Leptons ◽  
Emergent Quantum Mechanics

This paper addresses the long-standing question of how it may be explained that the three charged leptons (the electron, muon and tau particle) have different masses, despite their conformity in other respects. In the field of Emergent Quantum Mechanics non-singular electron models are being revisited, and from this exploration has come a possible answer. In this paper a deformable droplet model is considered. It is shown how the model can be made self-consistent, whilst obeying the laws of momentum and energy conservation as well as Larmor’s radiation law. The droplet appears to have three different static equilibrium configurations, each with a different mass. Tentatively, these three equilibrium masses were assumed to correspond with the measured masses of the charged leptons. The droplet model was tuned accordingly, and was thereby completely quantified. The dynamics of the droplet then showed a “De Broglie-like” relation p = K / λ . Beat patterns in the vibrations of the droplet play the role of the matter waves of usual quantum mechanics. The value of K , calculated by the droplet theory, practically equals Planck’s constant: K ≅ h . This fact seems to confirm the correctness of identifying the three types of charged leptons with the equilibria of a droplet of charge.

scholarly journals Quasinormal modes of dilatonic Reissner–Nordström black holes

2019 ◽  
Vol 79 (12) ◽  
Author(s):  
Jose Luis Blázquez-Salcedo ◽  
Sarah Kahlen ◽  
Jutta Kunz
Keyword(s):  
Black Holes ◽  
Quantitative Analysis ◽  
Electric Charge ◽  
Quasinormal Modes ◽  
Spherically Symmetric ◽  
Coupling Constant ◽  
Dilaton Coupling

AbstractWe calculate the quasinormal modes of static spherically symmetric dilatonic Reissner–Nordström black holes for general values of the electric charge and of the dilaton coupling constant. The spectrum of quasinormal modes is composed of five families of modes: polar and axial gravitational-led modes, polar and axial electromagnetic-led modes, and polar scalar-led modes. We make a quantitative analysis of the spectrum, revealing its dependence on the electric charge and on the dilaton coupling constant. For large electric charge and large dilaton coupling, strong deviations from the Reissner–Nordström modes arise. In particular, isospectrality is strongly broken, both for the electromagnetic-led and the gravitational-led modes, for large values of the charge.

scholarly journals Black hole and neutron star mergers in galactic nuclei: the role of triples

2019 ◽  
Vol 488 (2) ◽  
pp. 2825-2835 ◽  
Author(s):  
Giacomo Fragione ◽  
Nathan W C Leigh ◽  
Rosalba Perna
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Neutron Star ◽  
Massive Stars ◽  
Star Clusters ◽  
Galactic Nuclei ◽  
Compact Objects ◽  
Large Numbers ◽  
Binary Case

ABSTRACT Nuclear star clusters that surround supermassive black holes (SMBHs) in galactic nuclei are thought to contain large numbers of black holes (BHs) and neutron stars (NSs), a fraction of which form binaries and could merge by Kozai–Lidov oscillations (KL). Triple compact objects are likely to be present, given what is known about the multiplicity of massive stars, whose life ends either as an NS or a BH. In this paper, we present a new possible scenario for merging BHs and NSs in galactic nuclei. We study the evolution of a triple black hole (BH) or neutron star (NS) system orbiting an SMBH in a galactic nucleus by means of direct high-precision N-body simulations, including post-Newtonian terms. We find that the four-body dynamical interactions can increase the KL angle window for mergers compared to the binary case and make BH and NS binaries merge on shorter time-scales. We show that the merger fraction can be up to ∼5–8 times higher for triples than for binaries. Therefore, even if the triple fraction is only ∼10–$20\rm{\,per\,cent}$ of the binary fraction, they could contribute to the merger events observed by LIGO/VIRGO in comparable numbers.

scholarly journals The energetic role of massive stars in the AGN phenomenon

1999 ◽  
Vol 193 ◽  
pp. 703-715
Author(s):  
Timothy M. Heckman
Keyword(s):  
Black Holes ◽  
Massive Stars ◽  
Uv Light ◽  
Radiant Energy ◽  
Supermassive Black Holes ◽  
High Mass ◽  
Continuum Emission ◽  
Hot Stars

I review the evidence for a possible connection between AGN and starbursts and assess the energetic role of massive stars in the AGN phenomenon. My particular focus is on UV spectroscopy, since this is the energetically dominant spectral regime for the hot high-mass stars that power starbursts, and contains a wealth of spectral features for diagnosing the presence of such stars. I also review the non-stellar sources of UV line and continuum emission in AGN, including scattered or reprocessed light from the ‘central engine’. Spectroscopy directly shows that hot stars provide most of the UV light in about half of the brightest type 2 Seyfert nuclei and UV-bright LINERS. The population of hot stars in these AGN is typically heavily extinct and reddened by dust with A(1600Å) ≃ 2–4 mag. The implied intrinsic UV luminosities of the starburst range from 108 to 109 L⊙ in the LINERS to 1010 to 1011 L⊙ in the type 2 Seyferts. Massive stars play an energetically significant role in many AGN, but the causal or evolution connection between starbursts and AGN is unclear. I also consider the energetics of massive stars and accreting supermassive black holes from a global, cosmic perspective. Recent inventories in the local universe of the cumulative effect of nuclear burning (metal production) and of AGN-fueling (compact dark objects in galactic nuclei) imply that accretion onto supermassive black holes may have produced as much radiant energy as massive stars over the history of the universe.

scholarly journals Violation of the Dominant Energy Condition in Geometrodynamics

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 400
Author(s):  
Vladimir Lasukov
Keyword(s):  
Black Holes ◽  
Dark Energy ◽  
Energy Condition ◽  
Dominant Energy Condition ◽  
Isotropic Energy ◽  
Cosmological Singularity ◽  
Dominant Condition ◽  
Field Theoretical Model ◽  
Over Time

It is shown that in Einstein’s theory and in the theory of gravity with Logunov constraints, there is a field-theoretical model of dark energy that is consistent with the observational data indicating that the Hubble value increases over time. In the developed model of dark energy, the isotropic energy dominant condition is violated. It solves the problem of the cosmological singularity and the singularity of “black holes”. The compact configuration of the scalar field can generate a flux of particles by the pairs of particles production mechanism from the vacuum by a field of barrier and in the process of transformation of thermal energy (Hawking radiation) and acceleration energy into radiation. The scalars can play the role of the so-called “black holes” with no singularity inside themselves.

Sign in / Sign up

Export Citation Format

Share Document