CONJUGATED DIENE-BASED POLYMER, BRANCHING AGENT, PRODUCTION METHOD FOR CONJUGATED DIENE-BASED POLYMER, EXTENDED CONJUGATED DIENE-BASED POLYMER, RUBBER COMPOSITION, AND TIRE

A conjugated diene-based polymer of the present invention has an absolute molecular weight measured by viscosity detector-equipped GPC-light scattering measurement, of 40×10or more and 5000×10or less, has a branching number (Bn) measured by the viscosity detector-equipped GPC-light scattering measurement, of 8 or more, and has a modification ratio of 60% by mass or more.