Review for NeurIPS paper: Faster Randomized Infeasible Interior Point Methods for Tall/Wide Linear Programs

Neural Information Processing Systems 

Weaknesses: This paper provides a nice advance in the theory of infeasible-start long-step IPMs, however the novelty of the approach taken and the relation of the work in the paper to prior work could use further clarity. First, solving regression problems in an A in nearly linear time, when A has many more rows than columns has been the subject of a line of research, e.g. These results, including ones based on the subspace embedding result used in this paper, readily extend to solving linear systems in A T A and this has been used by the Theoretical Computer Science papers mentioned for implementing short step IPMs. Consequently, I think it would have been beneficial to state earlier that the paper is using the known linear system solving machinery of subspace embeddings to build preconditioners (rather than just saying that "Randomized Linear Algebra" is used) and put this in the context of prior work. There may be novelty in the particular way in which the paper is using conjugate gradient and subspace embeddings, however the paper would be strengthened if it articulated how this is different than this previous literature; as the appendix points out, conjugate gradient can be replaced with other iterative methods which possibly puts the approach considered closer to the ones from the literature. In light of the previous paragraph, I think more of the novelty in the paper may lie in exactly how they handle the error from approximate linear system solves in a way sensitive to the design of the preconditioner.