On the Complexity of Some Problems in Linear Algebra
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Planar Graph Perfect Matching Is in NC
2018 IEEE 59th Annual Symposium on Foundations of Computer Science Planar Graph Perfect Matching is in NC Nima Anari Vijay V. Vazirani Computer Science Department Computer Science Department Stanford University University of California, Irvine [email protected] [email protected] Abstract—Is perfect matching in NC? That is, is there a finding a perfect matching, was obtained by Karp, Upfal, and deterministic fast parallel algorithm for it? This has been an Wigderson [11]. This was followed by a somewhat simpler outstanding open question in theoretical computer science for algorithm due to Mulmuley, Vazirani, and Vazirani [17]. over three decades, ever since the discovery of RNC matching algorithms. Within this question, the case of planar graphs has The matching problem occupies an especially distinguished remained an enigma: On the one hand, counting the number position in the theory of algorithms: Some of the most of perfect matchings is far harder than finding one (the former central notions and powerful tools within this theory were is #P-complete and the latter is in P), and on the other, for discovered in the context of an algorithmic study of this NC planar graphs, counting has long been known to be in problem, including the notion of polynomial time solvability whereas finding one has resisted a solution. P In this paper, we give an NC algorithm for finding a perfect [4] and the counting class # [22]. The parallel perspective matching in a planar graph. Our algorithm uses the above- has also led to such gains: The first RNC matching algorithm stated fact about counting matchings in a crucial way. -
On Uniformity Within NC
On Uniformity Within NC David A Mix Barrington Neil Immerman HowardStraubing University of Massachusetts University of Massachusetts Boston Col lege Journal of Computer and System Science Abstract In order to study circuit complexity classes within NC in a uniform setting we need a uniformity condition which is more restrictive than those in common use Twosuch conditions stricter than NC uniformity RuCo have app eared in recent research Immermans families of circuits dened by rstorder formulas ImaImb and a unifor mity corresp onding to Buss deterministic logtime reductions Bu We show that these two notions are equivalent leading to a natural notion of uniformity for lowlevel circuit complexity classes Weshow that recent results on the structure of NC Ba still hold true in this very uniform setting Finallyweinvestigate a parallel notion of uniformity still more restrictive based on the regular languages Here we givecharacterizations of sub classes of the regular languages based on their logical expressibility extending recentwork of Straubing Therien and Thomas STT A preliminary version of this work app eared as BIS Intro duction Circuit Complexity Computer scientists have long tried to classify problems dened as Bo olean predicates or functions by the size or depth of Bo olean circuits needed to solve them This eort has Former name David A Barrington Supp orted by NSF grant CCR Mailing address Dept of Computer and Information Science U of Mass Amherst MA USA Supp orted by NSF grants DCR and CCR Mailing address Dept of -
Modeling, Inference and Clustering for Equivalence Classes of 3-D Orientations Chuanlong Du Iowa State University
Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2014 Modeling, inference and clustering for equivalence classes of 3-D orientations Chuanlong Du Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Statistics and Probability Commons Recommended Citation Du, Chuanlong, "Modeling, inference and clustering for equivalence classes of 3-D orientations" (2014). Graduate Theses and Dissertations. 13738. https://lib.dr.iastate.edu/etd/13738 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Modeling, inference and clustering for equivalence classes of 3-D orientations by Chuanlong Du A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Statistics Program of Study Committee: Stephen Vardeman, Co-major Professor Daniel Nordman, Co-major Professor Dan Nettleton Huaiqing Wu Guang Song Iowa State University Ames, Iowa 2014 Copyright c Chuanlong Du, 2014. All rights reserved. ii DEDICATION I would like to dedicate this dissertation to my mother Jinyan Xu. She always encourages me to follow my heart and to seek my dreams. Her words have always inspired me and encouraged me to face difficulties and challenges I came across in my life. I would also like to dedicate this dissertation to my wife Lisha Li without whose support and help I would not have been able to complete this work. -
Nitin Saurabh the Institute of Mathematical Sciences, Chennai
ALGEBRAIC MODELS OF COMPUTATION By Nitin Saurabh The Institute of Mathematical Sciences, Chennai. A thesis submitted to the Board of Studies in Mathematical Sciences In partial fulllment of the requirements For the Degree of Master of Science of HOMI BHABHA NATIONAL INSTITUTE April 2012 CERTIFICATE Certied that the work contained in the thesis entitled Algebraic models of Computation, by Nitin Saurabh, has been carried out under my supervision and that this work has not been submitted elsewhere for a degree. Meena Mahajan Theoretical Computer Science Group The Institute of Mathematical Sciences, Chennai ACKNOWLEDGEMENTS I would like to thank my advisor Prof. Meena Mahajan for her invaluable guidance and continuous support since my undergraduate days. Her expertise and ideas helped me comprehend new techniques. Her guidance during the preparation of this thesis has been invaluable. I also thank her for always being there to discuss and clarify any matter. I am extremely grateful to all the faculty members of theory group at IMSc and CMI for their continuous encouragement and giving me an opportunity to learn from them. I would like to thank all my friends, at IMSc and CMI, for making my stay in Chennai a memorable one. Most of all, I take this opportunity to thank my parents, my uncle and my brother. Abstract Valiant [Val79, Val82] had proposed an analogue of the theory of NP-completeness in an entirely algebraic framework to study the complexity of polynomial families. Artihmetic circuits form the most standard model for studying the complexity of polynomial computations. In a note [Val92], Valiant argued that in order to prove lower bounds for boolean circuits, obtaining lower bounds for arithmetic circuits should be a rst step. -
Lecture 12 – the Permanent and the Determinant
Lecture 12 { The permanent and the determinant Uriel Feige Department of Computer Science and Applied Mathematics The Weizman Institute Rehovot 76100, Israel [email protected] June 23, 2014 1 Introduction Given an order n matrix A, its permanent is X Yn per(A) = aiσ(i) σ i=1 where σ ranges over all permutations on n elements. Its determinant is X Yn σ det(A) = (−1) aiσ(i) σ i=1 where (−1)σ is +1 for even permutations and −1 for odd permutations. A permutation is even if it can be obtained from the identity permutation using an even number of transpo- sitions (where a transposition is a swap of two elements), and odd otherwise. For those more familiar with the inductive definition of the determinant, obtained by developing the determinant by the first row of the matrix, observe that the inductive defini- tion if spelled out leads exactly to the formula above. The same inductive definition applies to the permanent, but without the alternating sign rule. The determinant can be computed in polynomial time by Gaussian elimination, and in time n! by fast matrix multiplication. On the other hand, there is no polynomial time algorithm known for computing the permanent. In fact, Valiant showed that the permanent is complete for the complexity class #P , which makes computing it as difficult as computing the number of solutions of NP-complete problems (such as SAT, Valiant's reduction was from Hamiltonicity). For 0/1 matrices, the matrix A can be thought of as the adjacency matrix of a bipartite graph (we refer to it as a bipartite adjacency matrix { technically, A is an off-diagonal block of the usual adjacency matrix), and then the permanent counts the number of perfect matchings. -
Statistical Problems Involving Permutations with Restricted Positions
STATISTICAL PROBLEMS INVOLVING PERMUTATIONS WITH RESTRICTED POSITIONS PERSI DIACONIS, RONALD GRAHAM AND SUSAN P. HOLMES Stanford University, University of California and ATT, Stanford University and INRA-Biornetrie The rich world of permutation tests can be supplemented by a variety of applications where only some permutations are permitted. We consider two examples: testing in- dependence with truncated data and testing extra-sensory perception with feedback. We review relevant literature on permanents, rook polynomials and complexity. The statistical applications call for new limit theorems. We prove a few of these and offer an approach to the rest via Stein's method. Tools from the proof of van der Waerden's permanent conjecture are applied to prove a natural monotonicity conjecture. AMS subject classiήcations: 62G09, 62G10. Keywords and phrases: Permanents, rook polynomials, complexity, statistical test, Stein's method. 1 Introduction Definitive work on permutation testing by Willem van Zwet, his students and collaborators, has given us a rich collection of tools for probability and statistics. We have come upon a series of variations where randomization naturally takes place over a subset of all permutations. The present paper gives two examples of sets of permutations defined by restricting positions. Throughout, a permutation π is represented in two-line notation 1 2 3 ... n π(l) π(2) π(3) ••• τr(n) with π(i) referred to as the label at position i. The restrictions are specified by a zero-one matrix Aij of dimension n with Aij equal to one if and only if label j is permitted in position i. Let SA be the set of all permitted permutations. -
Computational Complexity: a Modern Approach
i Computational Complexity: A Modern Approach Draft of a book: Dated January 2007 Comments welcome! Sanjeev Arora and Boaz Barak Princeton University [email protected] Not to be reproduced or distributed without the authors’ permission This is an Internet draft. Some chapters are more finished than others. References and attributions are very preliminary and we apologize in advance for any omissions (but hope you will nevertheless point them out to us). Please send us bugs, typos, missing references or general comments to [email protected] — Thank You!! DRAFT ii DRAFT Chapter 9 Complexity of counting “It is an empirical fact that for many combinatorial problems the detection of the existence of a solution is easy, yet no computationally efficient method is known for counting their number.... for a variety of problems this phenomenon can be explained.” L. Valiant 1979 The class NP captures the difficulty of finding certificates. However, in many contexts, one is interested not just in a single certificate, but actually counting the number of certificates. This chapter studies #P, (pronounced “sharp p”), a complexity class that captures this notion. Counting problems arise in diverse fields, often in situations having to do with estimations of probability. Examples include statistical estimation, statistical physics, network design, and more. Counting problems are also studied in a field of mathematics called enumerative combinatorics, which tries to obtain closed-form mathematical expressions for counting problems. To give an example, in the 19th century Kirchoff showed how to count the number of spanning trees in a graph using a simple determinant computation. Results in this chapter will show that for many natural counting problems, such efficiently computable expressions are unlikely to exist. -
The Geometry of Convex Cones Associated with the Lyapunov Inequality and the Common Lyapunov Function Problem∗
Electronic Journal of Linear Algebra ISSN 1081-3810 A publication of the International Linear Algebra Society Volume 12, pp. 42-63, March 2005 ELA www.math.technion.ac.il/iic/ela THE GEOMETRY OF CONVEX CONES ASSOCIATED WITH THE LYAPUNOV INEQUALITY AND THE COMMON LYAPUNOV FUNCTION PROBLEM∗ OLIVER MASON† AND ROBERT SHORTEN‡ Abstract. In this paper, the structure of several convex cones that arise in the studyof Lyapunov functions is investigated. In particular, the cones associated with quadratic Lyapunov functions for both linear and non-linear systems are considered, as well as cones that arise in connection with diagonal and linear copositive Lyapunov functions for positive linear systems. In each of these cases, some technical results are presented on the structure of individual cones and it is shown how these insights can lead to new results on the problem of common Lyapunov function existence. Key words. Lyapunov functions and stability, Convex cones, Matrix equations. AMS subject classifications. 37B25, 47L07, 39B42. 1. Introduction and motivation. Recently, there has been considerable inter- est across the mathematics, computer science, and control engineering communities in the analysis and design of so-called hybrid dynamical systems [7,15,19,22,23]. Roughly speaking, a hybrid system is one whose behaviour can be described math- ematically by combining classical differential/difference equations with some logic based switching mechanism or rule. These systems arise in a wide variety of engineer- ing applications with examples occurring in the aircraft, automotive and communi- cations industries. In spite of the attention that hybrid systems have received in the recent past, important aspects of their behaviour are not yet completely understood. -
Structural Results on Matching Estimation with Applications to Streaming∗
Structural Results on Matching Estimation with Applications to Streaming∗ Marc Bury, Elena Grigorescu, Andrew McGregor, Morteza Monemizadeh, Chris Schwiegelshohn, Sofya Vorotnikova, Samson Zhou We study the problem of estimating the size of a matching when the graph is revealed in a streaming fashion. Our results are multifold: 1. We give a tight structural result relating the size of a maximum matching to the arboricity α of a graph, which has been one of the most studied graph parameters for matching algorithms in data streams. One of the implications is an algorithm that estimates the matching size up to a factor of (α + 2)(1 + ") using O~(αn2=3) space in insertion-only graph streams and O~(αn4=5) space in dynamic streams, where n is the number of nodes in the graph. We also show that in the vertex arrival insertion-only model, an (α + 2) approximation can be achieved using only O(log n) space. 2. We further show that the weight of a maximum weighted matching can be ef- ficiently estimated by augmenting any routine for estimating the size of an un- weighted matching. Namely, given an algorithm for computing a λ-approximation in the unweighted case, we obtain a 2(1+")·λ approximation for the weighted case, while only incurring a multiplicative logarithmic factor in the space bounds. The algorithm is implementable in any streaming model, including dynamic streams. 3. We also investigate algebraic aspects of computing matchings in data streams, by proposing new algorithms and lower bounds based on analyzing the rank of the Tutte-matrix of the graph. -
The Complexity Zoo
The Complexity Zoo Scott Aaronson www.ScottAaronson.com LATEX Translation by Chris Bourke [email protected] 417 classes and counting 1 Contents 1 About This Document 3 2 Introductory Essay 4 2.1 Recommended Further Reading ......................... 4 2.2 Other Theory Compendia ............................ 5 2.3 Errors? ....................................... 5 3 Pronunciation Guide 6 4 Complexity Classes 10 5 Special Zoo Exhibit: Classes of Quantum States and Probability Distribu- tions 110 6 Acknowledgements 116 7 Bibliography 117 2 1 About This Document What is this? Well its a PDF version of the website www.ComplexityZoo.com typeset in LATEX using the complexity package. Well, what’s that? The original Complexity Zoo is a website created by Scott Aaronson which contains a (more or less) comprehensive list of Complexity Classes studied in the area of theoretical computer science known as Computa- tional Complexity. I took on the (mostly painless, thank god for regular expressions) task of translating the Zoo’s HTML code to LATEX for two reasons. First, as a regular Zoo patron, I thought, “what better way to honor such an endeavor than to spruce up the cages a bit and typeset them all in beautiful LATEX.” Second, I thought it would be a perfect project to develop complexity, a LATEX pack- age I’ve created that defines commands to typeset (almost) all of the complexity classes you’ll find here (along with some handy options that allow you to conveniently change the fonts with a single option parameters). To get the package, visit my own home page at http://www.cse.unl.edu/~cbourke/. -
Chapter 0 Preliminaries
Chapter 0 Preliminaries Objective of the course Introduce basic matrix results and techniques that are useful in theory and applications. It is important to know many results, but there is no way I can tell you all of them. I would like to introduce techniques so that you can obtain the results you want. This is the standard teaching philosophy of \It is better to teach students how to fish instead of just giving them fishes.” Assumption You are familiar with • Linear equations, solution sets, elementary row operations. • Matrices, column space, row space, null space, ranks, • Determinant, eigenvalues, eigenvectors, diagonal form. • Vector spaces, basis, change of bases. • Linear transformations, range space, kernel. • Inner product, Gram Schmidt process for real matrices. • Basic operations of complex numbers. • Block matrices. Notation • Mn(F), Mm;n(F) are the set of n × n and m × n matrices over F = R or C (or a more general field). n • F is the set of column vectors of length n with entries in F. • Sometimes we write Mn;Mm;n if F = C. A1 0 • If A = 2 Mm+n(F) with A1 2 Mm(F) and A2 2 Mn(F), we write A = A1 ⊕ A2. 0 A2 • xt;At denote the transpose of a vector x and a matrix A. • For a complex matrix A, A denotes the matrix obtained from A by replacing each entry by its complex conjugate. Furthermore, A∗ = (A)t. More results and examples on block matrix multiplications. 1 1 Similarity, Jordan form, and applications 1.1 Similarity Definition 1.1.1 Two matrices A; B 2 Mn are similar if there is an invertible S 2 Mn such that S−1AS = B, equivalently, A = T −1BT with T = S−1. -
Analysis and Verification of Arithmetic Circuits Using Computer Algebra Approach
University of Massachusetts Amherst ScholarWorks@UMass Amherst Doctoral Dissertations Dissertations and Theses March 2020 ANALYSIS AND VERIFICATION OF ARITHMETIC CIRCUITS USING COMPUTER ALGEBRA APPROACH TIANKAI SU University of Massachusetts Amherst Follow this and additional works at: https://scholarworks.umass.edu/dissertations_2 Part of the VLSI and Circuits, Embedded and Hardware Systems Commons Recommended Citation SU, TIANKAI, "ANALYSIS AND VERIFICATION OF ARITHMETIC CIRCUITS USING COMPUTER ALGEBRA APPROACH" (2020). Doctoral Dissertations. 1868. https://doi.org/10.7275/15875490 https://scholarworks.umass.edu/dissertations_2/1868 This Open Access Dissertation is brought to you for free and open access by the Dissertations and Theses at ScholarWorks@UMass Amherst. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of ScholarWorks@UMass Amherst. For more information, please contact [email protected]. ANALYSIS AND VERIFICATION OF ARITHMETIC CIRCUITS USING COMPUTER ALGEBRA APPROACH A Dissertation Presented by TIANKAI SU Submitted to the Graduate School of the University of Massachusetts Amherst in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY February 2020 Electrical and Computer Engineering c Copyright by Tiankai Su 2020 All Rights Reserved ANALYSIS AND VERIFICATION OF ARITHMETIC CIRCUITS USING COMPUTER ALGEBRA APPROACH A Dissertation Presented by TIANKAI SU Approved as to style and content by: Maciej Ciesielski, Chair George S. Avrunin, Member Daniel Holcomb, Member Weibo Gong, Member Christopher V. Hollot, Department Head Electrical and Computer Engineering ABSTRACT ANALYSIS AND VERIFICATION OF ARITHMETIC CIRCUITS USING COMPUTER ALGEBRA APPROACH FEBRUARY 2020 TIANKAI SU B.Sc., NORTHEAST DIANLI UNIVERSITY Ph.D., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Maciej Ciesielski Despite a considerable progress in verification of random and control logic, ad- vances in formal verification of arithmetic designs have been lagging.