  We examine the problem of gathering $k \geq 2$ agents (or multi-agent
rendezvous) in dynamic graphs which may change in every synchronous round but
remain always connected ($1$-interval connectivity) [KLO10]. The agents are
identical and without explicit communication capabilities, and are initially
positioned at different nodes of the graph. The problem is for the agents to
gather at the same node, not fixed in advance. We first show that the problem
becomes impossible to solve if the graph has a cycle. In light of this, we
study a relaxed version of this problem, called weak gathering. We show that
only in unicyclic graphs weak gathering is solvable, and we provide a
deterministic algorithm for this problem that runs in polynomial number of
rounds.
