Do you some code to reproduce the issue?

Also, how exactly does e_x relate to x_triples?
I assume you want to compute the hessian for each embedding vector e_i? So, you’d have an output of k hessian matrices?
Also, are the embeddings e_i, e_j, and e_k three random embeddings from the list of embeddings stated at the beginning or three components of the an embedding e_i?