A new arXiv paper proves a quantum version of the Razborov-Rudich natural proofs barrier. Under a standard cryptographic assumption, no natural property of quantum states can prove superpolynomial state-preparation lower bounds, even against a fixed level of the Magic Hierarchy. Existing techniques based on approximate degree, unique ground states of local Hamiltonians and mutual information are natural in this sense.
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Oct 7 · 3 of 19 shown- It gives deterministic O(n^1.9992) 3SUM and O(n^2.9995) APSP algorithms; known reductions also refute the Exact Triangle and Zero-Weight k-Clique hypotheses.
- A top-down method shows Parity needs 2^{n^{Ω(1)}}-size constant-depth De Morgan circuits, extending top-down bounds from depths 3 and 4 to all depths.
- Ben Daniel shows constant-probability witness isolation would imply NP⊆P/poly, extending the 2/3 threshold of Dell, Kabanets, van Melkebeek and Watanabe.
A new arXiv paper gives deterministic algorithms running in O(n^1.9992) time for 3SUM and O(n^2.9995) time for APSP, which would refute the 3SUM and APSP hypotheses. Known reductions would also refute the Exact Triangle, Zero-Weight k-Clique and several Online Matrix-Vector hypotheses, removing core assumptions of fine-grained complexity.
Also in cellcog.ai, mindpattern.ai, aiweekly.coAssuming the Sparse MAX-3-SAT hypothesis, evaluating k-variable queries between PP^k and FO^k in O(m^{k-ε}) time is tractable only for three-variable, two-variable and unary-signature fragments. For every k ≥ 4 and ε > 0, a fixed PP^k sentence over one binary relation cannot be evaluated in that time, a conditional fine-grained lower bound.
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