  We provide a general self-attention formulation to impose group equivariance
to arbitrary symmetry groups. This is achieved by defining positional encodings
that are invariant to the action of the group considered. Since the group acts
on the positional encoding directly, group equivariant self-attention networks
(GSA-Nets) are steerable by nature. Our experiments on vision benchmarks
demonstrate consistent improvements of GSA-Nets over non-equivariant
self-attention networks.
