It is a little bit confusing that someone is explaining that BERT is using sinusoidal functions for BERT position encoding and someone is saying BERT just uses absolute position.
I checked that Vaswani 2017 et al., used a sinusoidal function for position embedding, but not sure BERT used the same technique since the BERT paper does not mention it much.
My question is
- Did BERT use absolute position embedding that is learnable, not with sinusoidal function?
- If so, is the absolute position the same dimension as the input embedding dimension for an addition?