English

Tensor Rank and Complexity

Algebraic Geometry 2022-08-01 v2 Computational Complexity

Abstract

These lecture notes are intended as an introduction to several notions of tensor rank and their connections to the asymptotic complexity of matrix multiplication. The latter is studied with the exponent of matrix multiplication, which will be expressed in terms of tensor (border) rank, (border) symmetric rank and the asymptotic rank of certain tensors. We introduce the multilinear rank of a tensor as well, deal with the concept of tensor equivalence and study prehomogeneous vector spaces with the castling transform. Moreover, we treat Apolarity Theory and use it to determine the symmetric rank (Waring rank) of some symmetric tensors.

Keywords

Cite

@article{arxiv.2004.01492,
  title  = {Tensor Rank and Complexity},
  author = {Giorgio Ottaviani and Philipp Reichenbach},
  journal= {arXiv preprint arXiv:2004.01492},
  year   = {2022}
}

Comments

46 pages; some major adjustments and additions in Section 2 (especially on castling transforms) and Section 6; further minor revisions in other sections