Abstract We study the variation of gravitational constant on cosmological scales in scalar-tensor theories gravity. focus simplest models with a coupling to Ricci scalar form F ( ? ) = N 2 pl + ?? , such as extended Jordan-Brans-Dicke 0), or non-minimally coupled field M which permits vary self-consistently time and space. In addition, we allow effective differ from Newton's measured G i.e. eff...

We revisit the quantum cosmological constant problem and highlight important roles played by de Sitter (dS) horizon of zero-point energy. argue that fields which are light enough to have a dS energy comparable Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) Hubble radius main contributors dark On other hand, heavy develop nonlinearities on sub-Hubble scales cannot contribute speculate our propo...