Instance Checking and the Permanent: Graduate Complexity Lecture 16 at CMU

Instance Checking and the Permanent: Graduate Complexity Lecture 16 at CMU

🎙 Ryan O'Donnell 👥 14K 📅 November 5, 2017 ⏱ 80 min 👁 541 📄 lecture 🧭 2026-08-17
Available in: English (current) Français

Keywords

permanentinstance checkingdownward self-reductionrandom self-reductionpolynomial identity testing

Summary

This graduate lecture on computational complexity theory, taught by Ryan O’Donnell at Carnegie Mellon University, explores the concept of instance checking, focusing on the permanent problem. The lecture begins by motivating the topic through SAT and its downward self-reducibility, which allows verification of a claimed SAT solver. It then introduces the permanent and its properties, including downward self-reducibility and random self-reducibility. The main content is divided into two cases: when a purported permanent-computing circuit is algebraic, and when it is Boolean. For algebraic circuits, the lecture shows how to verify correctness using polynomial identity testing (PIT), which is in coRP via the Schwartz-Zippel lemma. For Boolean circuits, verification is harder, but a probabilistic approach can still provide confidence. The lecture also discusses implications for circuit lower bounds and the relationship between derandomization and circuit complexity. The presentation is rigorous, with references to prior lectures and the Arora-Barak textbook.

148 words

Critical Evaluation

Value of the Information & Strength of the Argument

The lecture provides deep insights into instance checking and the permanent, highlighting the power of algebraic properties like downward and random self-reducibility. The argumentation is solid, building from known results (SAT, Karp-Lipton) to new concepts. The distinction between algebraic and Boolean circuits is well-motivated, and the use of polynomial identity testing is clearly explained. The lecture also connects to broader themes like derandomization and circuit lower bounds, offering a coherent narrative.

Scientific Rigor, Source Quality, Title Accuracy

The lecture is scientifically rigorous, with clear definitions and proofs. It references the Arora-Barak textbook and prior lectures, providing a solid foundation. The title accurately reflects the content, focusing on instance checking and the permanent. The lecture is part of a graduate course, indicating a high level of technical depth. No external sources are cited beyond the course materials, but the content is well-grounded in established complexity theory.

154 words

Title / Content Match

The title accurately reflects the content: the lecture focuses on instance checking and the permanent, with detailed discussion of algebraic and Boolean circuits.

Quality & Reliability

8/10

The lecture is part of a graduate course at Carnegie Mellon University, taught by a recognized expert in theoretical computer science. The content is rigorous, well-structured, and based on established results in computational complexity theory. The presentation is clear and technically accurate, with appropriate references to the textbook and prior lectures.

Key Moments

Cited Sources

Concurring Sources

Contribution & Novelties

The lecture provides a clear and detailed exposition of instance checking for the permanent, contrasting algebraic and Boolean circuits. It highlights the power of algebraic properties like random self-reducibility and connects to broader themes in complexity theory, such as derandomization and circuit lower bounds. The lecture also offers a constructive approach to verifying claimed algorithms, which is valuable for both theoretical and practical perspectives.

Pour aller plus loin :

124 words

Radar Profile

The radar profile shows high scores across all dimensions, indicating a lecture with substantial information content, strong technical depth, and high reliability. The balanced profile suggests a well-rounded presentation suitable for advanced students.

Reliability 8/10