Reparametrization Invariant Scaling Symmetry and the Value of the Einstein Cosmological Constant Λ_E

Abstract The nature of Dark Energy (DE) remains an enigma. This work explores the non-zero Einstein Cosmological Constant (Λ E ) as a manifestation of DE – viewing it through the lens of Reparametrization Invariant Scaling Symmetry (RISS), where Λ E is interpreted as a “kinetic energy” term within the energy density. The scale factor λ ( t ) relevant for cosmic reparametrization removes Λ E from the extended Einstein GR, its defining equations, and their relations to Λ E are derived. The value for Λ E = 1.8 × 10 −52 m −2 is consistent with the current observations for Λ E . The current approach avoids the puzzles associated with interpreting Λ E as vacuum zero-point energy (often called dark energy). Further applications are related to the Dark Matter problem by insisting on a reparametrization symmetry for the equations of motion, where un-proper (non-co-moving) time parametrization gives rise to fictitious forces.