508 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Istanbul Technical UniversityTR35 papers
- University of Wisconsin–MadisonUS26 papers
- Istanbul UniversityTR20 papers
- Middle East Technical UniversityTR20 papers
- University of Notre DameUS20 papers
- University of TrentoIT20 papers
- Boğaziçi UniversityTR19 papers
- University of IowaUS19 papers
- Centre National de la Recherche ScientifiqueFR18 papers
- Özyeğin UniversityTR18 papers
- Universität HamburgDE18 papers
- University of AlabamaUS18 papers
13 papers · 1 filter
f(R) Gravity in an Ellipsoidal Universe
Cemsinan Deliduman, Oguzhan Kasikci, Vildan Keles Tugyanoglu
We propose a new model of cosmology based on an anisotropic background and a specific theory of gravity. It is shown that field equations of gravity in a Bianchi type…
Wahlquist Metric Revisited
M. Hortaçsu
Here we continue studying the Wahlquist metric. We know that the wave equation written for a zero mass scalar particle in the background of this metric gives Heun type solutions. T…
A massless scalar particle coupled to the Wahlquist metric
T. Birkandan, M. Hortacsu
We study the solutions of the wave equation where a massless scalar field is coupled to the Wahlquist metric, a type-D solution. We first take the full metric and then write simpli…
The radial Teukolsky equation for Kerr-Newman-de Sitter geometry: Revisited
M. Hortacsu
We use Heun type solutions given in \cite{Suzuki} for the radial Teukolsky equation, written in the background metric of the Kerr-Newman-de Sitter geometry, to calculate the quasin…
Spherical and cylindrical solutions in f (T) gravity by Noether Symmetry Approach
Ali Nur Nurbaki, Salvatore Capozziello, Cemsinan Deliduman
We find exact solutions for f (T) teleparallel gravity for the cases of spherically and cylindrically symmetric tetrads. The adopted method is based on the search for Noether symme…
Non-minimally coupled quartic inflation with Coleman-Weinberg one-loop corrections in the Palatini formulation
Nilay Bostan
We discuss how the non-minimal coupling between the inflaton and the Ricci scalar affects predictions of single field inflation models in Palatini formalism. To transition…
Gravitational Lensing in Weyl Gravity
Oguzhan Kasikci, Cemsinan Deliduman
We calculate the deflection angle of light from a distant source by a galaxy cluster in Weyl's conformal gravity. The general method of calculation is first applied to calculate th…
Exact solution of the wave equation of a scalar particle in the zero mass limit of Kerr and Kerr-(anti-)de-Sitter space-times
T. Birkandan, M. Hortaçsu
Heun-type exact solutions emerge for both the radial and the angular equations for the case of a scalar particle coupled to the zero mass limit of both the Kerr and Kerr-(anti)de-S…
Einstein gravity with torsion induced by the scalar field
H. T. Özçelik, R. Kaya, M. Hortaçsu
We couple a conformal scalar field in (2+1) dimensions to Einstein gravity with torsion. The field equations are obtained by a variational principle. We could not solve the Einstei…
Flat Galactic Rotation Curves from Geometry in Weyl Gravity
Cemsinan Deliduman, Oguzhan Kasikci, Baris Yapiskan
We searched for a resolution of the flat galactic rotation curve problem from geometry instead of assuming the existence of dark matter. We observed that the scale independence of…
Neutron star solutions in perturbative quadratic gravity
Cemsinan Deliduman, K. Y. Ekşi, Vildan Keleş
We study the structure of neutron stars in R+β R^{μν} R_{μν} gravity model with perturbative method. We obtain mass--radius relations for six representative equations of state (EoS…
Absence of Relativistic Stars in f(T) Gravity
Cemsinan Deliduman, Baris Yapiskan
In this work we investigate the structure of neutron stars in modified f(T) gravity models. We find that, unlike the f(R) models, the equations of motion put a rather strict constr…
Constraints on Perturbative f(R) Gravity via Neutron Stars
A. Savas Arapoglu, Cemsinan Deliduman, K. Yavuz Eksi
We study the structure of neutron stars in perturbative f(R) gravity models with realistic equations of state. We obtain mass-radius relations in a gravity model of the form f(R)=R…