VPSPACE and a transfer theorem over the complex field

  • Authors:
  • Pascal Koiran;Sylvain Perifel

  • Affiliations:
  • LIP (UMR 5668 ENS Lyon, CNRS, UCBL, INRIA), École Normale Supérieure de Lyon, 46 allée dItalie, 69364 Lyon Cedex 07, France;LIAFA (Université Paris DiderotParis 7 and CNRS), Case 7014, 75205 Paris Cedex 13, France

  • Venue:
  • Theoretical Computer Science
  • Year:
  • 2009

Quantified Score

Hi-index 5.23

Visualization

Abstract

We extend the transfer theorem of [14] to the complex field. That is, we investigate the links between the class VPSPACE of families of polynomials and the Blum-Shub-Smale model of computation over C. Roughly speaking, a family of polynomials is in VPSPACE if its coefficients can be computed in polynomial space. Our main result is that if (uniform, constant-free) VPSPACE families can be evaluated efficiently, then the class PAR"C of decision problems that can be solved in parallel polynomial time over the complex field collapses to P"C. As a result, one must first be able to show that there are VPSPACE families which are hard to evaluate in order to separate P"C from NP"C, or even from PAR"C.