Tianqi Yang | Does a Range Avoidance Oracle Help Solve Decision Problems?

Tianqi Yang | Does a Range Avoidance Oracle Help Solve Decision Problems?

🎙 Tianqi Yang 👥 2K 📅 October 9, 2026 ⏱ 107 min 👁 34 📄 original study 🧭 2026-10-09
Available in: English (current) Français

Keywords

Range Avoidance ProblemArthur-Merlin protocolP_RASPdecision treescircuit complexity

Summary

The talk presents results on the complexity of the Range Avoidance Problem (RASP). It first reviews known facts: RASP is in BPP, but believed not to be in P. The speaker then shows that any polynomial-time algorithm with access to a RASP oracle can be simulated in AM, implying P^RASP ⊆ AM. Additionally, promise versions are also contained in AM. The proof uses a decision tree representation of the oracle algorithm and an Arthur-Merlin protocol where Merlin provides proofs of membership and the computation is simulated via random sampling. The talk addresses technicalities such as circuits with different range sizes and makes the protocol a constant-round AM protocol. The talk also mentions connections to cryptography and explicit constructions.

118 words

Critical Evaluation

Value of the Information & Strength of the Argument

This talk provides a significant novel result: P^RASP is contained in AM, which is surprising given that RASP is believed to be hard. The argumentation is rigorous, relying on standard complexity theory tools such as decision trees and probabilistic arguments. The proof is clearly presented, walking the audience through the construction of an AM protocol that simulates a polynomial-time algorithm with a RASP oracle. The value lies in clarifying the power of a range avoidance oracle, showing it does not elevate problems beyond the class AM. The argumentation is solid and well-motivated, despite being a seminar sketch rather than a fully detailed paper.

Scientific Rigor, Source Quality, Title Accuracy

The talk is given at the Isaac Newton Institute, a renowned research center, and the speaker is an academic from Columbia University. The content is rooted in established complexity theory, referencing known results and building upon them. The title perfectly aligns with the content: the central question is whether a range avoidance oracle helps solve decision problems, and the talk provides definitive answers. No public comments were available for analysis, so this assessment is based solely on the technical content.

198 words

Title / Content Match

The title accurately describes the focus on the computational complexity implications of a range avoidance oracle.

Quality & Reliability

9/10

Seminar at the Isaac Newton Institute presenting original research in computational complexity. The speaker is a researcher from Columbia University. The content is technical and rigorous, rooted in established complexity theory.

Key Moments

Cited Sources

Contribution & Novelties

The talk presents an original contribution by proving that P^RASP is contained in AM, which is a strong containment result for a problem believed to be hard. This clarifies the computational power of a range avoidance oracle, showing it does not exceed the second level of the polynomial hierarchy in a certain sense. The proof technique, using a decision tree and an AM protocol with randomness from a hash function, is innovative.

Pour aller plus loin :

  • Arthur–Merlin protocol — Relevant complexity class central to the talk’s results.
  • Computational complexity theory — General background on complexity classes and oracles.
  • Range Avoidance Problem — Note: This Wikipedia page does not exist, but the problem is discussed in complexity literature; for further reading, one might consult recent papers on the topic.

129 words

Radar Profile

The radar profile indicates a seminar with very high technical depth and information quality, balanced by equally high reliability. The scores suggest an advanced audience, as the level of technicality is maximized, but the content is solid and well-sourced.

Reliability 9/10