Speaker
Описание
Abstract
Gravitational waves (GWs) are independent of any particular theory of gravity. The universality of this notion is highlighted by the Raychaudhuri equation which is independent of any theory of gravity. This equation contains the Ricci tensor R as a key ingredient, thereby connecting spacetime geometry with matter-energy content. Under small metric perturbations, R is proportional to h where h is the perturbation. This indicates that different gravity theories, via their corresponding different Ricci tensors R , produce different gravitational wave equations. In the framework of Einstein's gravity, this leads to the standard gravitational wave equation. We first briefly describe the geometric nature of the Raychaudhuri equations and then show how the standard gravitational wave equations follow when the Raychaudhuri equation is used in Einstein gravity theory.
Links
• From geometry to observation: gravitational waves and the Raychaudhuri equation, Sougata Bhunia, Anubhab Dutta, Debashis Gangopadhyay, Goutam Manna, Physics of the Dark Universe V50, 102089 , (2025)
• Non -affine extensions of the Raychaudhuri equation in the K-essence framework, Samit Ganguly, Goutam Manna, Debashis Gangopadhyay, Eduardo Guendelman, Abhijit Bhattacharyya, Physics Letters B868 , 139622, (2025)
• NEC violation in f(R,T) gravity in the context of a non-canonical theory via modified Raychaudhuri equation, Arijit Panda, Debashis Gangopadhyay, Goutam Manna , Astroparticle Physics 165 , 103059 (2025) (available online https://doi.org/10.1016/j.astropartphys.2024.103059)
• Form Invariance of Raychaudhuri equation in the presence of Inflaton-type fields, Arijit Panda, Debashis Gangopadhyay, Goutam Manna , Fortschr. Phys. 2024 , 2400134 (2024)
• An Accelerated Universe with Negative Equation of state parameter in Inhomogeneous Cosmology with k-essence Scalar field, Somnath Mukherjee and Debashis Gangopadhyay, Physics of the Dark Universe 32, 100800, (2021)