This paper explores a new class of modified gravity models, called generalized Chern-Pontryagin models, which incorporate the Chern-Pontryagin topological term into the action, and investigates the consistency of various metrics, including perturbed Schwarzschild and Gödel-type metrics, within this framework.
本文論證了在廣義 f(R) 重力模型中,只有 Starobinsky 模型 (n = 2) 能夠自然地解釋為何在現今宇宙中觀測不到高秩反對稱張量場的影響,而其他 f(R) 模型則與此觀測結果相矛盾。
본 논문에서는 스하우텐 텐서와 코다찌 텐서를 기반으로 하는 새로운 중력 이론인 "스하우텐-코다찌 중력"(SCG)을 제안하고, 이 이론을 통해 정적 구형 대칭, FLRW 모델, 구형 먼지 유체와 같은 특정 시공간에서의 정확한 해를 도출하여 일반 상대성 이론과의 차이점을 비교 분석합니다.
This paper introduces Schouten-Codazzi Gravity (SCG), a new second-order phenomenological gravity theory based on the Schouten and Codazzi tensors, and explores its potential as an alternative to General Relativity by deriving and analyzing exact solutions for various spacetimes.
This research paper explores the complexity of self-gravitating systems within Degenerate Higher-Order Scalar-Tensor (DHOST) theories by employing orthogonal splitting of the Riemann curvature tensor to derive structure scalars, revealing insights into the impact of modified gravity on stellar structures.
본 논문에서는 체른-사이먼스-가우스-보넷(CS-GB) 중력 이론에서 수정된 장 방정식을 유도하고, 이 수정된 이론이 프리드만-르메트르-로버트슨-워커, 슈바르츠실트, 구형 대칭, 섭동된 민코프스키 메트릭을 포함한 기본 메트릭에 미치는 영향을 탐구합니다.
This paper derives and presents the complete set of field equations in Chern-Simons-Gauss-Bonnet gravity for various fundamental metrics (FLRW, Schwarzschild, spherically symmetric, and perturbed Minkowski) to lay the groundwork for future investigations into the observational consequences and testability of this modified gravity theory.
This research paper investigates the potential of f(T) gravity, a modified theory of gravity, to explain the observed accelerated expansion of the universe and the nature of dark energy, concluding that the power law model of f(T) gravity aligns closely with the standard cosmological model (ΛCDM) when tested against observational data.
Semi-Symmetric Metric Gravity (SSMG), a modified gravity theory incorporating torsion, offers a compelling alternative to the standard cosmological model by potentially explaining cosmic acceleration and galactic dynamics without invoking dark matter or a cosmological constant.
本研究使用重子聲速狀態方程式和 Pantheon+ 資料集,對線性和非線性 Weyl-type f(Q, T) 重力模型進行統計分析,並與 ΛCDM 模型進行比較,以探討其作為描述宇宙晚期加速膨脹的可行性。