The Complexity of the Path-following Solutions of Two-dimensional Sperner/Brouwer Functions

Paul W. Goldberg

Home/Archive/arXiv

arXiv · 1506.04882

The Complexity of the Path-following Solutions of Two-dimensional Sperner/Brouwer Functions

Paul W. Goldberg

View original source ↗Read source document ↗Export metadata ↓

Abstract

There are a number of results saying that for certain "path-following" algorithms that solve PPAD-complete problems, the solution obtained by the algorithm is PSPACE-complete to compute. We conjecture that these results are special cases of a much more general principle, that all such algorithms compute PSPACE-complete solutions. Such a general result might shed new light on the complexity class PPAD. In this paper we present a new PSPACE-completeness result for an interesting challenge instance for this conjecture. Chen and Deng~\cite{CD} showed that it is PPAD-complete to find a trichromatic triangle in a concisely-represented Sperner triangulation. The proof of Sperner's lemma --- that such a solution always exists --- identifies one solution in particular, that is found via a natural "path-following" approach. Here we show that it is PSPACE-complete to compute this specific solution, together with a similar result for the computation of the path-following solution of two-dimensional discrete Brouwer functions.

Explore related subjects

cs.CC

Keep this discovery

BibTeX RIS

Paul W. Goldberg. 2015-06-16. The Complexity of the Path-following Solutions of Two-dimensional Sperner/Brouwer Functions. https://arxiv.org/abs/1506.04882

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

The Computational Complexity of Holant Problems on 4-regular Graphs from the Stable Subgroup Sequence of $SL(2,\mathbb{C})$

The Holant framework provides a general setting for studying counting problems and includes graph homomorphisms (\#GH) and counting constraint satisfaction problems (\#CSP) as special cases. Over the past twenty years, a series of computational complexity dichotomies have been established for Holant problems, but the classification for complex-valued signatures is still open. The main obstacle is the case in which all signatures have even arity. In this paper, we establish a dichotomy for Holant problems with a complex-valued 4-ary signature, which is a key base case for the full classification of Holant problems. We present a new strategy by introducing Schur's theorem, the classification of finite subgroups of $\mathrm{SL}(2,\mathbb{C})$ and stable subgroup sequences into the proof. These new techniques are of independent interest.

cs.CC↗

arXiv2026

Max Independent Set Remains NP-hard when Excluding a Planar Induced Minor

We show that there is a fixed planar graph $H$, namely the $5 \times 5$ grid, such that Max Independent Set remains NP-hard in $H$-induced-minor-free graphs. This refutes the Dallard--Milani\v{c}--\v{S}torgel conjecture and a weakening of it by Gartland and Lokshtanov, and by Korhonen.

cs.CC↗

arXiv2026

Topology inside NC$^1$

We show that ACC$^0$ is precisely what can be computed with constant-width circuits of polynomial size and polylogarithmic genus. This extends a characterization given by Hansen, showing that planar constant-width circuits also characterize ACC$^0$. Thus polylogarithmic genus provides no additional computational power in this model. We consider other generalizations of planarity, including crossing number and thickness. We show that constant-width circuits of polynomial size and thickness two already suffice to capture all of NC$^1$.

cs.CC↗