At present, there is no widely accepted and complete theory that combines both general relativity and quantum mechanics in a fully consistent manner. The two pillars of modern physics, general relativity and quantum mechanics, have been tremendously successful in their respective domains but are inherently incompatible when it comes to describing certain phenomena, such as the behavior of gravity on the quantum scale.
Efforts to develop a theory that encompasses both general relativity and quantum mechanics are actively pursued in the field of theoretical physics. Various approaches have been proposed, including string theory, loop quantum gravity, and other quantum gravity models. These theories aim to provide a framework that incorporates both quantum mechanics and general relativity, thereby addressing the challenges that arise when trying to reconcile the two theories.
However, it's important to note that these approaches are still under active research, and no definitive experimental evidence or consensus has emerged to establish one as the definitive theory of quantum gravity. The search for a fully relativistic quantum theory remains an ongoing endeavor in theoretical physics.