Dilaton-induced variations in Planck constant and speed of light: An alternative to Dark Energy

We reveal a novel aspect of scale-invariant actions that allow matter to couple with a dilaton field: $$The dynamics of the dilaton can induce variations in the Planck constant $\mathrm{\hslash }$ and speed of light $c$. $$Our mechanism for generating variable $\mathrm{\hslash }$ and $c$ in $\mathit{\text{curved}}$ spacetimes via the dilaton offers a viable alternative account for late-time cosmic acceleration, bypassing the need for dark energy.