Title
Affine projections of polynomials
Abstract
An m-variate polynomial f is said to be an affine projection of some n-variate polynomial g if there exists an nxm matrix A and an n-dimensional vector b such that f (x) = g(Ax + b). In other words, if f can be obtained by replacing each variable of g by an affine combination of the variables occurring in f, then it is said to be an affine projection of g. Given f and g can we determine whether f is an affine projection of g ? Some well known problems (such as VP versus VNP and matrix multiplication for example) are instances of this problem. The intention of this paper is to understand the complexity of the corresponding computational problem: given polynomials f and g find A and b such that f = g(Ax + b), if such an (A, b) exists. We first show that this is an NP-hard problem. We then focus our attention on instances where g is a member of some fixed, well known family of polynomials so that the input consists only of the polynomial f (x) having m variables and degree d. We consider the situation where f (x) is given to us as a blackbox (i.e. for any point a is an element of F-m we can query the blackbox and obtain f (a) in one step) and devise randomized algorithms with running time poly(mnd) in the following special cases: (1) when f = Perm(n) (Ax + b) and A satisfies rank(A) = n(2). Here Perm(n) is the permanent polynomial. (2) when f = Det(n)(Ax + b) and A satisfies rank(A) = n(2). Here Det(n) is the determinant polynomial. (3) when f = Pow(n,d)(Ax + b) and A is a random nxm matrix with d = n(Omega(1)). Here Pow(n,d) is the power-symmetric polynomial of degree d. (4) when f = SPSn,d(Ax + b) and A is a random (nd) x m matrix with n constant. Here SPSn,d is the sum-of-products polynomials of degree d with n terms.
Year
Venue
Keywords
2011
STOC'12: PROCEEDINGS OF THE 2012 ACM SYMPOSIUM ON THEORY OF COMPUTING
Affine Projection,Depth Three Circuit,Determinant,Permanent,Polynomial Equivalence,Reconstruction,Waring Problem for Polynomials
Field
DocType
Volume
Affine transformation,Affine involution,Discrete mathematics,Combinatorics,Affine combination,Polynomial,Affine coordinate system,Macdonald polynomials,Affine hull,Geometric complexity theory,Mathematics
Journal
18
Citations 
PageRank 
References 
2
0.35
0
Authors
1
Name
Order
Citations
PageRank
Neeraj Kayal126319.39