How successful can the scalar-tensor theory be in understanding the accelerating universe?

Understand

The accelerating universe is closely related to today's version of the cosmological constant problem; fine-tuning and coincidence problems.

• We show how successfully the scalar-tensor theory, a rather rigid theoretical idea, provides us with a simple and natural way to understand why today's observed cosmological constant is small only because we are old cosmologically, without fine-tuning theoretical parameters extremely.