1. A method for generating an implied object graph, the method comprising: identifying a plurality of user behaviors by an online system, each user behavior comprising an interaction with an object of a plurality of objects and performed by a user of a plurality of users of the online system; generating a plurality of local object graphs, each local object graph associated with a user of the plurality of users and comprising a subset of the objects with which the user interacted and links between objects of the subset; determining a weight for each of the links in the local object graphs, the weight determined based on the corresponding user behavior; merging the plurality of local object graphs to generate a global object graph, the global object graph comprising the plurality of objects and links between the plurality of objects; determining a weight for each of the links in the global object graph based on the weights of the merged local object graphs; and storing the links and the corresponding weights from the global object graph in an adjacency matrix.