Published by the Department of Computer Science, The University of Chicago.
Meena Mahajan
The Institute of Mathematical Sciences,
Chennai 600113, India
meena AT imsc DOT res DOT india
Guillaume Malod
Univ Paris Diderot, Sorbonne Paris Cité
IMJ-PRG, UMR 7586 CNRS
Sorbonne Université
UPMC Univ Paris 06, F-75013, Paris, France.
malod AT math DOT univ-paris-diderot DOT fr
Nicolas de Rugy-Altherre
Univ Paris Diderot, Sorbonne Paris Cité
IMJ-PRG, UMR 7586 CNRS
Sorbonne Université
UPMC Univ Paris 06, F-75013, Paris, France.
nderugy AT math DOT univ-paris-diderot DOT fr
Nitin Saurabh
The Institute of Mathematical Sciences,
Chennai 600113, India
nitin AT imsc DOT res DOT in
The VP versus VNP question, introduced by Valiant, is probably the most important open question in algebraic complexity theory. Thanks to completeness results, a variant of this question, VBP versus VNP, can be succinctly restated as asking whether the permanent of a generic matrix can be written as a determinant of a matrix of polynomially bounded size. Strikingly, this restatement does not mention any notion of computational model. To get a similar restatement for the original and more fundamental question, and also to better understand the class itself, we need a complete polynomial for VP. Ad hoc constructions yielding complete polynomials were known, but not natural examples in the vein of the determinant. We give here several variants of natural complete polynomials for VP, based on the notion of graph homomorphism polynomials.
Submitted February 4, 2015, revised December 6, 2016, and on March 11,
2016, published March 18, 2016.