Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userVectorial and spinorial perturbations in Galileon Black Holes: Quasinormal modes, quasiresonant modes and stability
74
0
0.0
(
0
)
Added by
Jeferson de Oliveira
Publication date
2018
fields
Physics
and research's language is
English
Ask ChatGPT about the research
No Arabic abstract
In this work we have considered a model that includes the interaction of gravity and matter fields with Galilean invariance (the so-called derivative coupling) as well as some corresponding black hole type solutions. Quasinormal perturbations of two kinds of matter fields have been computed by different methods. The effect of the derivative coupling in the quasinormal spectrum has been analyzed and evaluated.
rate research
Read More
Loop Quantum Gravity (LQG) is a theory that proposes a way to model the behavior of the spacetime in situations where its atomic characteristic arises. Among these situations, the spacetime behavior near the Big Bang or black holes singularity. The detection of gravitational waves, on the other hand, has opened the way to new perspectives in the investigation of the spacetime structure. In this work, by the use of a WKB method introduced by Schutz and Will cite{Schutz:1985zz}, and after improved by Iyer and Will cite{s.iyer-prd35}, we study the gravitational wave spectrum emitted by loop quantum black holes, which correspond to a quantized version of the Schwarzschild spacetime by LQG techniques. From the results obtained, loop quantum black holes have been shown stable under axial gravitational perturbations.
In this work, we have calculated the polar gravitational quasinormal modes for a quantum corrected black hole model, that arises in the context of Loop Quantum Gravity, known as Self-Dual Black Hole. In this way, we have calculated the characteristic frequencies using the WKB approach, where we can verify a strong dependence with the Loop Quantum Gravity parameters. At the same time we check that the Self-Dual Black Hole is stable under polar gravitational perturbations, we can also verify that the spectrum of the polar quasinormal modes differs from the axial one cite{Cruz:2015bcj}. Such a result tells us that isospectrality is broken in the context of Self Dual Black Holes.
A solution to the black hole information problem requires propagation of information from the interior of the black hole to the exterior. Such propagation violates general relativity and could conceivably be accomplished through firewall models. Based on the existence of similar firewalls at the inner horizons of charged and rotating black holes, a model of a firewall was recently constructed where the exterior spacetime reduces to that of the Schwarzschild metric but with a dramatically different interior. We investigate the radial and nonradial polar stability of these objects. We first study the dynamics of the shell under spherically symmetric perturbations, and impose constraints on the firewall model parameters by requiring a subluminal speed of sound on the firewall. We show that the demands of stability and subluminality impose significant constraints on the internal parameters of the firewall, narrowing down the range of objects that could be used to create such a structure.
Black holes found in binaries move at very high velocities relative to our own reference frame and can accelerate due to the emission of gravitational radiation. Here, we investigate the numerical stability and late-time behavior of linear scalar perturbations in accelerating black holes described by the $C-$metric. We identify a family of quasinormal modes associated with the photon surface and a brand new family of purely imaginary modes associated with the boost parameter of the accelerating black hole spacetime. When the accelerating black hole is charged, we find a third family of modes which dominates the ringdown waveform near extremality. Our frequency and time domain analysis indicate that such spacetimes are stable under scalar fluctuations, while the late-time behavior follows an exponential decay law, dominated by quasinormal modes. This result is in contrast with the common belief that such perturbations, for black holes without a cosmological constant, always have a power-law cutoff. In this sense, our results suggest that the asymptotic structure of black hole backgrounds does not always dictate how radiative fields behave at late times.
The rapid advancement of gravitational wave astronomy in recent years has paved the way for the burgeoning development of black hole spectroscopy, which enhances the possibility of testing black holes by their quasinormal modes (QNMs). In this paper, the axial gravitational perturbations and the QNM frequencies of black holes in the hybrid metric-Palatini gravity (HMPG) are investigated. The HMPG theory is characterized by a dynamical scalar degree of freedom and is able to explain the late-time accelerating expansion of the universe without introducing any textit{ad hoc} screening mechanism to preserve the dynamics at the Solar System scale. We obtain the master equation governing the axial gravitational perturbations of the HMPG black holes and calculate the QNM frequencies. Moreover, in the scrutiny of the black holes and their QNMs, we take into account the constraints on the model parameters based on the post-Newtonian analysis, and show how the QNM frequencies of the HMPG black holes would be altered in the observationally consistent range of parameter space.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
