Title
Deterministic Identity Testing for Sum of Read-once Oblivious Arithmetic Branching Programs.
Abstract
A read-once oblivious arithmetic branching program (ROABP) is an arithmetic branching program (ABP) where each variable occurs in at most one layer. We give the first polynomial time whitebox identity test for a polynomial computed by a sum of constantly many ROABPs. We also give a corresponding blackbox algorithm with quasi-polynomial time complexity nO(log n). In both the cases, our time complexity is double exponential in the number of ROABPs. ROABPs are a generalization of set-multilinear depth-3 circuits. The prior results for the sum of constantly many set-multilinear depth-3 circuits were only slightly better than brute-force, i.e. exponential-time. Our techniques are a new interplay of three concepts for ROABP: low evaluation dimension, basis isolating weight assignment and low-support rank concentration. We relate basis isolation to rank concentration and extend it to a sum of two ROABPs using evaluation dimension (or partial derivatives).
Year
DOI
Venue
2015
10.1007/s00037-016-0141-z
Conference on Computational Complexity
Keywords
Field
DocType
Polynomial identity testing, hitting-sets, sum of ROABPs, 68Q25, 68W30
Discrete mathematics,Combinatorics,Polynomial,Binary decision diagram,Arithmetic,Identity testing,Time complexity,Double exponential function,Mathematics,Branching (version control)
Conference
Volume
Issue
ISSN
26
4
1420-8954
Citations 
PageRank 
References 
5
0.43
27
Authors
4
Name
Order
Citations
PageRank
Rohit Gurjar1386.80
Arpita Korwar2293.60
Nitin Saxena328026.72
Thomas Thierauf428833.59