94 citations · 253 across the 15 of their papers we have counts for
15 papers
The generalized second law for Kerr-Taub-NUT black holes perturbed by test field
Koray Düztaş, Ahmet Cem Erdoğan
We evaluate the variations in the area and the entropy of Kerr-Taub-NUT black holes perturbed by bosonic and fermionic test fields. We demonstrate that the critical frequency for a…
Dual entropy gain by radiation at the zero temperature limit
Koray Düztaş
Recently we have demonstrated that black hole radiation can be smoothly extended to the zero-temperature limit. Here we analyse entropy variations at the zero temperature limit and…
Self energy in Kerr-Sen space-time incorporated to overspinning and overcharging problems
Koray Düztaş
Previous attempts to overspin or overcharge Kerr-Sen black holes have been incomplete, as they neglect back-reaction effects. In this study, we incorporate the self-energy of pertu…
Can the induced increase in the angular velocity prevent the overspinning of BTZ black holes?
Koray Düztaş
Previously we showed that nearly extremal Bañados-Teitelboim-Zanelli (BTZ) black holes can be overspun by test bodies and fields, following the work of Rocha and Cardoso for the ex…
Spin-2 fields and cosmic censorship
Koray Düztaş
We evaluate the possibility of the formation of naked singularities in the interaction of Kerr black holes with test massless spin-2 fields. We analyse the scattering problem for b…
Challenging event horizons with spin (3/2) fields
Koray Düztaş
We attempt to destroy the event horizons of Kerr black holes by perturbing them with massless spin (3/2) fields. We carry out a detailed analysis by incorporating the explicit form…
Cosmic censorship, massless fermionic test fields, and absorption probabilities
Koray Düztaş
In the conventional approach, fermionic test fields lead to a generic overspinning of black holes resulting in the formation of naked singularities. The absorption of the fermionic…
Group theoretical formulation of free fall and projectile motion
Koray Düztaş
In this work we formulate the group theoretical description of free fall and projectile motion. We show that the kinematic equations for constant acceleration form a one parameter…
Coulomb fields as perturbations of type D vacuum space-times
Koray Düztaş
We consider a test, non-null electromagnetic field special in the sense that the principal null directions of the field lie along the two repeated principal null directions of the…
Hawking radiation as the cosmic censor
Koray Düztaş, İbrahim Semiz
Hawking radiation acts as a cosmic censor since it carries away the angular momentum of the black hole, proportionally more than its mass. In this work we first show that an extrem…
The decoupling problem of the Proca equation; and treatment of Dirac, Maxwell and Proca fields on the resulting pp-wave spacetimes
Koray Düztaş, İbrahim Semiz
In this work we take a formal approach to the problem of decoupling Proca equations in curved space-times. We use Newman-Penrose (NP) two-spinor formalism to represent the Proca ve…
Weak Cosmic Censorship, Superradiance and Quantum Particle Creation
İbrahim Semiz, Koray Düztaş
Since 1970's, gedanken experiments have been devised to challenge the weak cosmic censorship conjecture (WCCC), which is the expectation that spacetime singularities will be hidden…
Is there a mode stability paradox for neutrino perturbations of Kerr black holes?
Koray Düztaş
Adopting the notation of Teukolsky and Press, we derive the connection relation for asymptotic solutions of the massless Dirac equation on a Kerr background. We show that, unlike b…
Electromagnetic field and cosmic censorship
Koray Düztaş
We construct a gedanken experiment in which an extremal Kerr black hole interacts with a test electromagnetic field. Using Teukolsky's solutions for electromagnetic perturbations i…
Cosmic Censorship, Black Holes and Integer-spin Test Fields
Koray Düztaş, İbrahim Semiz
It has been argued that, starting with a slightly sub-extremal Kerr black hole instead of an extremal one, it is possible to overspin a black hole past the extremal limit and turn…