Title
Depth-4 Lower Bounds, Determinantal Complexity: A Unified Approach.
Abstract
Tavenas (Proceedings of mathematical foundations of computer science (MFCS), 2013) has recently proved that any \(n^{O(1)}\)-variate and degree n polynomial in \(\mathsf {VP}\) can be computed by a depth-4 \(\Sigma \Pi \Sigma \Pi \) circuit of size \(2^{O(\sqrt{n}\log n)}\). So, to prove \(\mathsf {VP}\ne \mathsf {VNP}\) it is sufficient to show that an explicit polynomial in \(\mathsf {VNP}\) of degree n requires \(2^{\omega (\sqrt{n}\log n)}\) size depth-4 circuits. Soon after Tavenas’ result, for two different explicit polynomials, depth-4 circuit-size lower bounds of \(2^{\Omega (\sqrt{n}\log n)}\) have been proved (see Kayal et al. in Proceedings of symposium on theory of computing, ACM, 2014b. http://doi.acm.org/10.1145/2591796.2591847; Fournier et al. in Proceedings of symposium on theory of computing, ACM, 2014). In particular, using a combinatorial design Kayal et al. (2014b) construct an explicit polynomial in \(\mathsf {VNP}\) that requires depth-4 circuits of size \(2^{\Omega (\sqrt{n}\log n)}\) and Fournier et al. (Proceedings of symposium on theory of computing, ACM, 2014) show that the iterated matrix multiplication polynomial (which is in \(\mathsf {VP}\)) also requires \(2^{\Omega (\sqrt{n}\log n)}\) size depth-4 circuits.
Year
DOI
Venue
2014
10.4230/LIPIcs.STACS.2014.239
STACS
Keywords
Field
DocType
Lower bounds, Determinantal complexity, Constant depth, Arithmetic circuits, 68Q17
Binary logarithm,Discrete mathematics,Combinatorics,Polynomial,Upper and lower bounds,Matrix (mathematics),Omega,Combinatorial design,Matrix multiplication,Iterated function,Mathematics
Conference
Volume
Issue
ISSN
28
4
1420-8954
Citations 
PageRank 
References 
4
0.46
3
Authors
2
Name
Order
Citations
PageRank
Suryajith Chillara1143.68
Partha Mukhopadhyay29112.71