Sürdürülebilir Kalkınma Amaçları

• 2

Araştırmacılar(1)

• Korunur, Sibel

• MakaleAçık Erişim2026/r/munzur/5948
  Energy density in Rainbow Gravity: Levi-Civita Model

  Korunur, Murat; Korunur, Sibel

  In this study, the energy density for the Levi-Civita space-time is analyzed within the framework of Rainbow Gravity Theory (RGT). RGT is a theoretical approach that assumes the geometry of space-time depends on the energy of the test particle, offering a promising perspective in the quest for quantum gravity. Energy densities are calculated using the Einstein, Bergmann-Thomson, and Landau-Lifshitz energy-momentum prescriptions and compared with the results obtained from General Relativity. The findings reveal that as the test particle’s energy increases, the energy density rises in the Einstein and Landau-Lifshitz prescriptions, while it decreases in the Bergmann-Thomson formulation. This highlights how the problem of energy localization varies across different energy-momentum definitions and demonstrates the impact of RGT on energy distribution. The study contributes to the literature exploring the influence of alternative gravitational theories on energy-momentum distributions.

  İncele
• MakaleYalnız künye2026Scopus SJRQ3/r/munzur/1273
  Rényi holographic dark energy-inspired model and scalar field reconstruction in bianchi type III spacetime

  Korunur, Murat; Korunur, Sibel

  In this study, we consider a cosmological model based on Rényi holographic dark energy within the context of an anisotropic Bianchi type III spacetime geometry. The dark energy density is taken as a modified function of the Hubble parameter, which enables us to express the Einstein field equations in a closed dynamical system. By solving these equations, we obtain the evolution of the Hubble parameter and examine the main cosmological implications of the model. The physical behavior of the universe is discussed through the analysis of the equation-of-state parameter as well as the deceleration parameter. Our results indicate that the universe evolves from an initial decelerated expansion phase toward a late-time accelerated regime. In the asymptotic limit, the model tends to a de Sitter phase, suggesting the presence of a stable attractor configuration. In addition, we reconstruct the dark energy component in terms of different scalar field frameworks, namely quintessence, tachyon, and k-essence models. The associated scalar fields and their potentials are derived and numerically investigated. The obtained results show a coherent late-time behavior, which is in agreement with the observed accelerated expansion of the universe. The small value of the mean anisotropy parameter indicates that this evolution occurs within a quasi-isotropic Bianchi type III background.

  İncele
• MakaleAçık Erişim2024/r/munzur/6337
  Teleparallel Energy Density within the Framework of Rainbow Gravitation Theory for A Spatial Self-Similar, Local Rotational Symmetric Model

  Korunur, Murat; Korunur, Sibel

  It is known that the general theory of relativity provides valuable answers about our universe. General relativity theory is used to describe space, time, and mass-energy interactions, while quantum theory is used to explain the behavior and interactions of microscopic particles. The gap between these two theories reveals the need to develop a unified theory of "quantum gravity". However, so far no universal theory has yet been found that fully resolves this conflict. This is a big puzzle that physicists have been working on for a long time, and unifying these two theories harmoniously is one of the biggest challenges in modern physics. One of the theories put forward for this purpose is the "Rainbow" theory of gravity. In this study, Einstein, Bergmann-Thomson and Landau-Lifshitz energy densities are calculated for a spatial self-similar, locally rotationally symmetric model using teleparallel geometry within the framework of the Rainbow theory of gravity. However, the results obtained are evaluated using rainbow functions that are well known in the literature. The obtained results are rewritten as explicit forms of energy densities for Einstein, Bergman-Thomson and Landau-Liftshitz representations using f_1 (\\chi)=1/(1-\\chi)and f_2 (\\chi)=1 rainbow functions. Accordingly, it has been shown that the test particle changes its energy density for the Einstein and Bergmann-Thomson energy-momentum prescriptions but does not change the energy density for the Landau-Liftshitz energy-momentum prescription.

  İncele
• MakaleYalnız künye2024Scopus SJRQ1/r/munzur/2093
  Sharma–Mittal holographic dark energy and scalar field in Bianchi type-I cosmology

  Korunur, Sibel

  In this work, we studied Sharma–Mittal holographic dark energy model by considering Bianchi type-I cosmology. For this purpose we analyzed equation of state parameter using IR cutoff scale. Also it is reconstructed correspondence between Sharma–Mittal holographic dark energy and tachyon and quintessence scalar fields. Finally, we created plots for the time-evolution of the equation of state, kinetic energy, and scalar potential.

  AtıfScopus3·WoS4·OpenAlex4

  İncele
• MakaleYalnız künye2024Scopus SJRQ2/r/munzur/1776
  Energy-Momentum distributions of cylindrical black hole in rainbow gravity

  Korunur, Murat; Korunur, Sibel

  In this study, the energy-momentum localization problem is addressed within the framework of rainbow gravity. Considering the black string black hole, one of the cylindrical black hole models, energy-momentum distributions are obtained for Einstein, Bergmann-Thomson, and Landau-Liftshitz prescriptions in rainbow gravity. All prescriptions' energy densities are non-zero and depend on the rainbow functions, while the momentum distributions are zero. It has been observed that space-time energy does not depend on the energy of the test particle for some particular choices of rainbow functions. The results obtained for all special cases are given in a table.

  AtıfScopus4·WoS4·OpenAlex4

  İncele
• MakaleAçık Erişim2023/r/munzur/5732
  Tsallis Holographic Dark Energy with Granda-Oliveros Scale in Bianchi-Type V Universe

  Korunur, Murat; Korunur, Sibel

  A wide variety of cosmological observations show us that our universe is in an accelerated expansion phase. Dark Energy and Dark Matter are thought to be two of the causes of this accelerated expansion. Therefore, scientists have recently been doing many studies on dark energy and matter. In particular, many energy density relations are written, and research is done about space-time structure. In this sense, the Tsallis holographic dark energy model is also in a current and interesting position. The study establishes a relationship between the Tsallis holographic dark energy (THDE) model and some scalar fields (quintessence, tachyon, dilaton scalar fields, etc.) specific to the Bianchi-type V space-time model. The relationship above is discussed within the Granda-Oliveros (GO) cut-off framework. The state equation parameter is calculated analytically, and the phase of our universe for this model is investigated with the graphs drawn. In addition, there is how the kinetic energy and the scalar potential change with time. The results are again analyzed numerically with graphs.

  İncele
• MakaleYalnız künye2023Scopus SJRQ2/r/munzur/1594
  Energy-momentum localization in rainbow gravity

  Korunur, Murat; Korunur, Sibel

  Theoretical physicists generally prefer to modify the general theory of relativity rather than avoiding the successful approaches that have been offered to us. Hence, the rainbow formalism of gravity, which is one of the most studied quantum gravity candidates in literature, has recently gained importance in the field. In this study, the energy-momentum localization problem is discussed for the Taub universe within the framework of rainbow gravity. To achieve this goal, energy and momentum components are calculated by making use of diverse values of rainbow functions in the Einstein, Bergmann-Thomson, Landau-Lifshitz, and the Papapetrou prescriptions for the geometry under consideration. Except for the Landau-Lifshitz prescription, all prescriptions depend on the rainbow functions and the momentum components vanish. Graphical analysis is performed for all the energies obtained. Also, it is shown in limiting condition f1(x) → 1; f2(x) → 1 that the results are compatible with the ones obtained in the general relativity.

  AtıfOpenAlex1

  İncele
• MakaleYalnız künye2022Scopus SJRQ2/r/munzur/2910
  Kaniadakis holographic dark energy with scalar field in Bianchi type-V universe

  Korunur, Sibel

  In this work, considering anisotropic and homogeneous Bianchi type-V universe we investigated Kaniadakis holographic dark energy (KHDE). It is demonstrated that the equation of state (EoS) parameter has a transition from the quintessence era to the phantom era for the chosen model. Additionally, in the late time of the universe, EoS parameter behaves like a cosmological constant (Λ) with an IR (Infrared) cut-off apparent horizon in case of a particular form of deceleration parameter. We reconstructed correspondence between the KHDE and tachyon, quintessence and k-essence scalar fields. Also, our numerical solutions have been shown in graphs for EoS parameter and scalar fields.

  AtıfScopus7·WoS8·OpenAlex9

  İncele
• MakaleAçık Erişim2022/r/munzur/2521
  Calculation of Dynamic Properties of Drug-Added Aqueous Solutions with T1 and T2 Relaxation Times; [İlaç Katkılı Sulu Çözeltilerin Dinamik Özelliklerinin T1 ve T2 Rölaksasyon Zamanları ile Hesaplanması]

  Korunur, Sibel

  The development of modern spectroscopic methods has facilitated and accelerated structure analysis. The NMR method is the most popular way to perform structural analysis of compounds with very complex structures. D2O is a solvent that is frequently used in NMR analysis of both chemical molecules and many biological molecules such as drugs, proteins, and enzymes. In this paper, the study of residual water in proton drug-added protein solutions was carried out via NMR relaxation. The spin-lattice (T1) and the spin-spin relaxation (T2) times of residual water in drug-added protein solutions were studied depending on temperature by Avance Bruker 400 MHz1H-NMR Spectrometer, and activation energies (E! ) and rotational correlation times (τ" and τ# ) have been determined for T1 and T2 relaxation times.

  İncele
• MakaleYalnız künye2019Scopus SJRQ2/r/munzur/3815
  Tsallis holographic dark energy in Bianchi type-III spacetime with scalar fields

  Korunur, Murat

  In this paper, we study one of the new dark energy models named Tsallis holographic dark energy (THDE) model considering the Bianchi type-III spacetime model. Considering deceleration parameter, transition from deceleration to acceleration phase happens at z = 0.256. The equation of state (EoS) parameter has been found using the Granda-Oliveros (GO) scale. It is found that for > 2 values, EoS parameter behaves like the quintessence era; for < 2, EoS parameter behaves like the phantom dark energy and approaches CDM model at late-time cosmic acceleration phase. Also, we reconstructed a correspondence between THDE model and some well-known scalar fields, such as tachyon, quintessence and K-essence. In addition, we evaluated equation of state parameter, kinetic energy and scalar potential versus time.

  AtıfScopus28·WoS28·OpenAlex29

  İncele