Théorie de la Complexité
Imprimer ce billetUn livre en ligne sur la théorie de la complexité :
Complexity Theory: A Modern Approach / Sanjeev Arora and Boaz Barak
avec un chapitre sur le calcul quantique.
Voici la table des matières :
Part I: Basic Complexity Classes
- The computational model – and why it doesn’t matter. Definition of Turing machine, efficient universal TM, the class P.
- NP and NP completeness. NP, Cook-Levin Theorem, NP-completeness, search vs. decision.
- Space Complexity PSPACE, L, NL. TQBF is PSPACE complete, Savitch’s Theorem, Path is NL-complete, NL=coNL.
- Diagonalization Time, Non-deterministic time, and space hierarchy theorems, Ladner’s theorem, oracle machines and proof that relativized methods can’t resolve P vs. NP.
- The polynomial hierarchy and alternations. Definitions of PH via alternating quantifiers and alternating machines, conjecture it doesn’t collapse, time-space tradeoffs for SAT.
- Circuits. Boolean circuits and the class Ppoly. Definition using advice. Karp-Lipton theorem. Non-uniform hierarchy theorem. circuit-satisfiability and alternative proof for Cook-Levin theorem.
- Randomized Computation BPP, RP, coRP, ZPP. Examples of probabilistic algorithms. Error reduction via repetition. BPP in P/poly and PH. Randomized reductions, randomized logspace algorithms.
- Complexity of Counting #P. #P-completeness and Valiant’s theorem. Toda’s theorem.
- Interactive Proofs IP, AM. Graph non-isormorphism in AM. IP=PSPACE.
- Cryptography One-way functions, pseudorandom generators: prediction vs. distinguishing. Goldreich-Levin theorem. Zero knowledge and ZK proof for graph isomorphism. Overview of advanced topics in cryptography.
Part II: Lower bounds for concrete computational models
- Decision Trees certificate complexity, randomized complexity, sorting lowerbounds
- Communication Complexity Lowerbound methods (fooling set, rank, tiling, discrepancy), multiparty communication complexity
- Circuit lowerbounds. Hastad switching lemma, lowerbounds for monotone circuits, frontier of circuit lowerbounds, approaches using communication complexity.
- Algebraic complexity Algebraic trees and circuits, Blum-Shub-Smale model.
Part III: Advanced Topics
- Average Case Complexity: Levin’s Theory DistNP and its complete problems.
- Random and pseudorandom walks on graphs second eigenvalue and analysis of random walks, expander graphs, zig-zag construction of expanders, reingold’s deterministic logspace algorithm for undirected connectivity.
- Derandomization and Extractors Pseudorandom generators from average-case hardness – the NW generators. Extractors from hash functions. Trevisan’s extractor from NW.
- Hardness amplification and error correcting codes Worst-case to average case reduction. Error correcting codes. Pseudoarndom generators from worst-case assumptions. List decoding and its use for hardness amplification.
- PCP and hardness of approximation. NP in PCP(poly,1). The PCP theorem (Dinur’s proof). Independent set is hard to approximate within a polynomial factor.
- More PCP Theorems and the Fourier Transform Technique Fourier transforms over GF(2)^n. Analysis of linearity testing. Hastad’s 3-query PCP, 3SAT is hard to 7/8+epsilon approximate. Learning fourier coefficients (Goldreich-Levin / Kushilevits-Mansour)
- Quantum Computation Quantum computation and the class QBP. Shor’s factoring algorithm.
- Logic in complexity theory Proof complexity.
- Why are circuit lower bounds so difficult? Natural proofs.
Commentaires fermés