Sparse circuits are defined as a set of nodes connected by edges."
...which could also be considered/viewed as Graphs...
(Then from earlier in the paper):
>"We train models to have more understandable circuits by constraining most of their weights to be zeros, so that each neuron only has a few connections. To recover fine-grained circuits underlying each of several hand-crafted tasks, we prune the models to isolate the part responsible for the task. These circuits often contain neurons and residual channels that correspond to natural concepts, with a small number of straightforwardly interpretable connections between them.
And (jumping around a bit more in the paper):
>"A major difficulty for interpreting transformers is that the activations and weights are not directly comprehensible; for example, neurons activate in unpredictable patterns that don’t correspond to human-understandable concepts. One hypothesized cause is superposition (Elhage et al., 2022b), the idea that dense models are an approximation to the computations of a much larger untangled sparse network."
A very interesting paper -- and a very interesting postulated potential relationship with superposition! (which also could be related to data compression... and if so, in turn, by relationship, potentially entropy as well...)
Anyway, great paper!