A New Perspective on the Cosmological Constant and Its Core Problems

One of the most enduring and unresolved challenges in modern theoretical and observational cosmology is the fine-tuning and coincidence problems associated with the cosmological constant. Rather than attempting to reconcile these issues within the standard LCDM framework where they remain effectively frozen, we adopt a fundamentally different viewpoint based on alternative theories of gravity. We argue that the root of these problems lies in a deep misinterpretation of the cosmological constant, particularly its identification with the quantum ground-state energy of spacetime. In this work, we propose a novel physical interpretation of the cosmological constant and introduce a new mechanism, termed Breaking Energy-Momentum Symmetry. This framework provides a natural and unified route toward alleviating, and potentially resolving, both the fine-tuning and coincidence problems, offering a compelling alternative to the conventional cosmological paradigm.