CONF rabeehkarimimahabadi_NEURIPS_2021/IDIAP Compacter: Efficient Low-Rank Hypercomplex Adapter Layers Karimi Mahabadi, Rabeeh Henderson, James Ruder, Sebastian EXTERNAL https://publications.idiap.ch/attachments/papers/2021/rabeehkarimimahabadi_NEURIPS_2021.pdf PUBLIC NeurIPS 2021