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

A conjugated diene-based polymer of the present invention has a branch number (Bn) measured by viscosity detector-equipped GPC-light scattering measurement of 8 or more, has a change (ΔT) of an oxidation onset temperature caused through application of a thermal load of 11.9°C or less, and contains an aromatic vinyl compound monomer unit.