Gravitational waves in Brans-Dicke Theory with a cosmological constant

Understand

Weak field gravitational wave solutions are investigated in Brans-Dicke (BD) theory in the presence of a cosmological constant.

• In this setting the background geometry is not flat but asymptotically de-Sitter.
• We investigate the linearised field equations, and their gravitational wave solutions in a certain gauge choice.
• We will show that this theory leads to massless scalar waves as in original BD theory and in contrast to massive BD theory.