Yazar "Eraslan, Erkan" seçeneğine göre listele

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  • [ X ]
    Öğe
    Accelerately Expanding Cosmologies in f(R,?,X) Theory
    (2023) Eraslan, Erkan; Doğru, Melis Ulu
    In this study, beginning and today expansion of universe are viewed in f(R,?,X) gravity. Field equations and their solutions of Friedmann-Lemaître-Robertson-Walker cosmologies with perfect fluid are obtained by considering f(R,?,X)=f_0 R+f_1 X^q-V(?) model. Validity of both f(R,?,X) gravity and f(R,?,X)=f_0 R+f_1 X^q-V(?) model for non-static space-time geometries is discussed by making use of the obtained matter dynamics results such as pressure and energy density. It is seen that in all obtained solutions by taking into account early and late period expansion, f function is a constant. This indicates that f(R,?,X) function is a first-order dependent function of Ricci scalar. When f(R,?,X)=f_0 R+f_1 X^q-V(?) model is considered together, it is understood that the obtained solutions could be reduced to ?-CDM model for f(R) gravity in limits of ??0 and X?0. The fact that the obtained results agree with expected situations supports. So, f(R,?,X) theory is a consistent theory of gravity.
  • [ X ]
    Öğe
    Compact objects in f(R,Lm) theory
    (World Scientific Publ Co Pte Ltd, 2025) Taşer, Doğukan; Doğru, Melis Ulu; Kirezli, Pınar; Aydın, Hüseyin; Eraslan, Erkan
    In this study, it is aimed to investigate the Krori-Barua type compact stars within the scope of f(R, L-m) theory. In this context, first, the field equations are obtained by considering the f(R, L-m) = R/2 + alpha L-m(n) model. Interestingly, the model offers chance to attain all components of matter without any restrictions. In addition, data sets from LMC X-4, EXO 1785-248 and Cen X-3 are used to analyze physical stability of the solutions. It is obtained that all conditions such as causality and stability. which indicate consistency between compact objects and f(R, L-m) theory are valid for the constructed model. We obtained that small values of n in the f(R, L-m) function show significant effect on the consistency of the star models. Therefore, different n values are considered for each star data set when graphing the physical states. Finally, necessary quantities of the model are defined, compared with the considered stars and discussed in detail.
  • Küçük Resim
    Öğe
    Conformal wormholes in f(R,Lm) theory
    (Iop Publishing Ltd, 2024) Taşer, Doğukan; Doğru, Melis Ulu; Eraslan, Erkan; Aydın, Hüseyin
    In this study, we present a new static and conformally symmetric wormhole solution. We develop new wormhole model in f(R,L-m) gravity. Shape function of conformally symmetric f(R,L-m) wormholes, provided by homothetic vector field is obtained regarding to conformal factor. It is investigated whether the function provides a stable throat infrastructure that does not allow collapsing. Anisotropic fluid matter filled the obtained conformally symmetric traversable wormholes is discussed by examining the dynamical properties of the fluid. Constructed new wormhole model violates all energy conditions. Physical significance of the sources filled constructed wormholes is discussed using volume quantifier. It is revealed that f(R,L-m) theory allows traversable and conformally symmetric wormholes if supported by phantom field.
  • Küçük Resim
    Öğe
    ??(??,??,??) teori
    (Çanakkale Onsekiz Mart Üniversitesi, 2023) Eraslan, Erkan; Doğru, Melis Ulu
    Bu çalışmada, alternatif gravitasyon teorilerinden biri olan 𝑓(𝑅,Φ,𝑋) Teori hakkında genel bilgi verilmiştir. 𝑓(𝑅,Φ,𝑋) Teori kapsamında sırasıyla, Schwarzschild tipi karadelik modeli, konformal küresel simetrik uzay-zamanda akışkan dağılımları, statik olmayan Friedmann-Lemaître-Robertson-Walker (FLRW) evreninde lineer bir 𝑓(𝑅,Φ,𝑋) modeli için akışkan dağılımları, kurt delikleri ve 𝑓(𝑅,Φ,𝑋) Teorinin enerji koşulları incelenmiştir. Elde edilen sonuçlar ve literatür bilgileri karşılaştırılarak 𝑓(𝑅,Φ,𝑋) Teorinin tutarlılığı ve geçerliliği tartışılmıştır.