Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userSpin-3/2 fields in $D$-dimensional Schwarzschild black hole space-times
144
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
In previous works we have studied spin-3/2 fields near 4-dimensional Schwarzschild black holes. The techniques we developed in that case have now been extended here to show that it is possible to determine the potential of spin-3/2 fields near $D$-dimensional black holes by exploiting the radial symmetry of the system. This removes the need to use the Newman-Penrose formalism, which is difficult to extend to $D$-dimensional space-times. In this paper we will derive a general $D$-dimensional gauge invariant effective potential for spin-3/2 fields near black hole systems. We then use this potential to determine the quasi-normal modes and absorption probabilities of spin-3/2 fields near a $D$-dimensional Schwarzschild black hole.
rate research
Read More
In this paper we consider spin-3/2 fields in a $D$-dimensional Reissner-Nordstrom black hole spacetime. As these spacetimes are not Ricci-flat, it is necessary to modify the covariant derivative to the supercovariant derivative, by including terms related to the background electromagnetic fields, so as to maintain the gauge symmetry. Using this supercovariant derivative we arrive at the corresponding Rarita-Schwinger equation in a charged black hole background. As in our previous works, we exploit the spherically symmetry of the spacetime and use the eigenspinor-vectors on an $N$-sphere to derive the radial equations for both non-transverse-traceless (non-TT) modes and TT modes. We then determine the quasi-normal mode and absorption probabilities of the associated gauge-invariant variables using the WKB approximation and the asymptotic iteration method. We then concentrate on how these quantities change with the charge of the black hole, especially when they reach the extremal limits.
The analysis of gravitino fields in curved spacetimes is usually carried out using the Newman-Penrose formalism. In this paper we consider a more direct approach with eigenspinor-vectors on spheres, to separate out the angular parts of the fields in a Schwarzschild background. The radial equations of the corresponding gauge invariant variable obtained are shown to be the same as in the Newman-Penrose formalism. These equations are then applied to the evaluation of the quasinormal mode frequencies, as well as the absorption probabilities of the gravitino field scattering in this background.
In June 2015 the Large Hadron Collider was able to produce collisions with an energy of 13TeV, where collisions at these energy levels may allow for the formation of higher dimensional black holes. In order to detect these higher dimensional black holes we require an understanding of their emission spectra. One way of determining this is by looking at the absorption probabilities associated with the black hole. In this proceedings we will look at the absorption probability for spin-3/2 particles near $N$-dimensional Schwarzschild black holes. We will show how the Unruh method is used to determine these probabilities for low energy particles. We then use the Wentzel-Kramers-Brillouin approximation in order to determine these absorption probabilities for the entire possible energy range.
Our understanding of black holes changed drastically, when Stephen Hawking discovered their evaporation due to quantum mechanical processes. One core feature of this effect is both its similarity and simultaneous dissimilarity to classical black body radiation: A black holes spectrum certainly looks like that of a black/grey body, yet the number of emitted particles per unit time differs greatly. However it is precisely this emission rate that determines whether the resulting radiation field behaves classically or non-classically. It has been known nearly since the effects discovery that a black holes radiation is in this sense non-classical. However, this has been an utterly underappreciated property. In order to give a more readily quantifiable picture of this, we introduced the easily evaluated and interpreted notion of sparsity. Sadly, and much to relativists chagrin, astrophysical black holes (and their evaporation) tend to be observationally elusive entities. Luckily, Hawkings derivation lends itself to reformulations that survive outside its astrophysical origin - only three things are needed: a universal speed limit, a notion of a horizon, and lastly a sprinkle of quantum dynamics on top. With these ingredients at hand, the last thirty-odd years have seen a lot of work to transfer Hawking radiation into the laboratory, using a range of physical models. A large part of this thesis is aimed at providing electromagnetic analogues to prepare an analysis of our notion of sparsity in these analogues. For this, we developed extensively a purely algebraic/kinematical analogy based on covariant meta-material electrodynamics, but also an analytic/dynamical analogy based on stratified refractive indices. After introducing these analogue space-time models, we explain why the notion of sparsity is much more subtle and difficult to come by than in the original, astrophysical setting.
We study the evaporation of black holes in non-commutative space-times. We do this by calculating the correction to the detectors response function for a moving mirror in terms of the noncommutativity parameter $Theta$ and then extracting the number density as modified by this parameter. We find that allowing space and time to be non-commutative increases the decay rate of a black hole.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
