Shadow cast and quasinormal modes in f(R) gravity model inspired by Yang–Mills field

2021 ◽  
pp. 2150143
Author(s):  
Younes Younesizadeh ◽  
Jennifer Liang
Keyword(s):  
Magnetic Charge ◽  
Null Geodesic ◽  
Quasinormal Modes ◽  
Third Order ◽  
Yang Mills ◽  
Shadow Cast ◽  
Schrödinger Form ◽  
Mills Field ◽  
Hamilton Jacobi Equation ◽  
Charge Formula

In this paper, the null geodesic equations are computed in [Formula: see text] space–time dimensions [Y. Younesizadeh, A. A. Ahmad, A. H. Ahmed, F. Younesizadeh, Ann. Phys. 420, 168246 (2020)] by using the concept of symmetries and Hamilton–Jacobi equation and Carter separable method. With these null geodesics in hand, we evaluate the celestial coordinates (x, y) and the radius [Formula: see text] of the BH shadow and represent it graphically. In addition, we have shown that the peak of this energy slowly shifts to lower frequencies and its height decreases with the increase in the YM magnetic charge ([Formula: see text]) values and decrease in the [Formula: see text] parameter ([Formula: see text]) values. In addition, we have analyzed the concept of effective potential barrier by transforming the radial equation of motion into standard Schrodinger form. The most important result derived from this study is that the height of this potential increases with increase in the YM magnetic charge ([Formula: see text]) values. Then, we study the quasinormal modes (QNMs) of these 4D black holes. For this purpose, we use the WKB approximation method upto third-order corrections. We have shown the perturbation’s decay in corresponding diagrams when the YM magnetic charge ([Formula: see text]) values and the [Formula: see text] parameter ([Formula: see text]) values change.

scholarly journals Shadow cast by a rotating and nonlinear magnetic-charged black hole in perfect fluid dark matter

2021 ◽  
pp. 2150112
Author(s):  
Tian-Chi Ma ◽  
He-Xu Zhang ◽  
Peng-Zhang He ◽  
Hao-Ran Zhang ◽  
Yuan Chen ◽  
...  
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Perfect Fluid ◽  
Emission Rate ◽  
Magnetic Charge ◽  
Spherically Symmetric ◽  
Intensity Parameter ◽  
Shadow Cast ◽  
Sgr A ◽  
Charge Formula

In this paper, we derived an exact solution of the spherically symmetric Hayward black hole surrounded by perfect fluid dark matter (PFDM). By applying the Newman–Janis algorithm, we generalized it to the corresponding rotating black hole. Then, we studied the shadows of rotating Hayward black hole in PFDM. The apparent shape of the shadow depends upon the black hole spin [Formula: see text], the magnetic charge [Formula: see text] and the PFDM intensity parameter [Formula: see text]. The shadow is a perfect circle in the non-rotating case [Formula: see text] and a deformed one in the rotating case [Formula: see text]. For a fixed value of [Formula: see text], the size of the shadow increases with the increasing [Formula: see text], but decreases with the increasing [Formula: see text]. We further investigated the black hole emission rate. We found that the emission rate decreases with the increasing [Formula: see text] (or [Formula: see text]) and the peak of the emission shifts to lower frequency. Finally, we discussed the observational prospects corresponding to the supermassive black hole Sgr A[Formula: see text] at the center of the Milky Way.

Dynamics of Magnetized and Magnetically Charged Particles around Regular Nonminimal Magnetic Black Holes

Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 71
Author(s):  
Javlon Rayimbaev ◽  
Bakhtiyor Narzilloev ◽  
Ahmadjon Abdujabbarov ◽  
Bobomurat Ahmedov
Keyword(s):  
Black Hole ◽  
Magnetic Charge ◽  
Coupling Parameter ◽  
Charged Particles ◽  
Kerr Black Hole ◽  
Harmonic Oscillations ◽  
Yang Mills ◽  
Keplerian Orbits ◽  
Maximum Value ◽  
Mills Field

The present paper is devoted to the study of the event horizon properties of spacetime around a regular nonminimal magnetic black hole (BH), together with dynamics of magnetized and magnetically charged particles in the vicinity of the BH. It is shown that the minimum value of the outer horizon of the extreme charged BH increases with the increase in coupling parameter. It reaches its maximum value of 1.5M when q→∞, while the maximal value of the BH charge decreases and tends toward zero. We also present a detailed analysis of magnetized particles’ motion around a regular nonminimal magnetic black hole. The particle’s innermost circular stable orbits (ISCOs) radius decreases as the magnetic charge and the parameter β increase and the coupling parameter of Yang–Mills field causes a decrease at the values of the magnetic charge near to its maximum. We show that the magnetic charge can mimic the spin of a rotating Kerr black hole up to the value of a=0.7893M, providing the same value for an ISCO of a magnetized particle with the parameter β=10.2 when the coupling parameter is q=0. Moreover, Lyapunov exponents, Keplerian orbits and harmonic oscillations of magnetized particles motion are also discussed.

scholarly journals Perturbative linearization of super-Yang-Mills theories in general gauges

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Hannes Malcha ◽  
Hermann Nicolai
Keyword(s):  
Large Class ◽  
Fourth Order ◽  
Landau Gauge ◽  
Third Order ◽  
Yang Mills ◽  
Free Theory ◽  
Non Linear ◽  
Functional Measure ◽  
Non Local ◽  
Jacobi Determinant

Abstract Supersymmetric Yang-Mills theories can be characterized by a non-local and non-linear transformation of the bosonic fields (Nicolai map) mapping the interacting functional measure to that of a free theory, such that the Jacobi determinant of the transformation equals the product of the fermionic determinants obtained by integrating out the gauginos and ghosts at least on the gauge hypersurface. While this transformation has been known so far only for the Landau gauge and to third order in the Yang-Mills coupling, we here extend the construction to a large class of (possibly non-linear and non-local) gauges, and exhibit the conditions for all statements to remain valid off the gauge hypersurface. Finally, we present explicit results to second order in the axial gauge and to fourth order in the Landau gauge.

Existence of Charged States of the Yang‐Mills Field

1970 ◽  
Vol 11 (11) ◽  
pp. 3258-3274 ◽  
Author(s):  
Hendricus G. Loos
Keyword(s):  
Yang Mills ◽  
Mills Field

FINITE ENERGY ONE-HALF MONOPOLE SOLUTIONS

2012 ◽  
Vol 27 (40) ◽  
pp. 1250233 ◽  
Author(s):  
ROSY TEH ◽  
BAN-LOONG NG ◽  
KHAI-MING WONG
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Topological Charge ◽  
Magnetic Monopole ◽  
Magnetic Charge ◽  
Finite Energy ◽  
Spatial Infinity ◽  
Yang Mills ◽  
The Magnetic Field

We present finite energy SU(2) Yang–Mills–Higgs particles of one-half topological charge. The magnetic fields of these solutions at spatial infinity correspond to the magnetic field of a positive one-half magnetic monopole at the origin and a semi-infinite Dirac string on one-half of the z-axis carrying a magnetic flux of [Formula: see text] going into the origin. Hence the net magnetic charge is zero. The gauge potentials are singular along one-half of the z-axis, elsewhere they are regular.

scholarly journals Magnetic charge superselection in the deconfined phase of Yang-Mills theory

2004 ◽  
Vol 69 (7) ◽  
Author(s):  
M. D’Elia ◽  
A. Di Giacomo ◽  
B. Lucini
Keyword(s):  
Magnetic Charge ◽  
Yang Mills

scholarly journals On the Mini-Superambitwistor Space and𝒩=8Super-Yang-Mills Theory

2009 ◽  
Vol 2009 ◽  
pp. 1-27 ◽  
Author(s):  
Christian Sämann
Keyword(s):  
Dimensional Reduction ◽  
Three Dimensions ◽  
Third Order ◽  
Yang Mills

We construct a new supertwistor space suited for establishing a Penrose-Ward transform between certain bundles over this space and solutions to the𝒩=8super-Yang-Mills equations in three dimensions. This mini-superambitwistor space is obtained by dimensional reduction of the superambitwistor space, the standard superextension of the ambitwistor space. We discuss in detail the construction of this space and its geometry before presenting the Penrose-Ward transform. We also comment on a further such transform for purely bosonic Yang-Mills-Higgs theory in three dimensions by considering third-order formal “subneighborhoods” of a miniambitwistor space.

scholarly journals Generalization of the Stueckelberg Formalism to the Massive Yang-Mills Field

1967 ◽  
Vol 37 (2) ◽  
pp. 452-464 ◽  
Author(s):  
T\=osaku Kunimasa ◽  
Tetsuo Got\=o
Keyword(s):  
Yang Mills ◽  
Stueckelberg Formalism ◽  
Mills Field
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