#undecidability
Two Searches That Would Break Computability

Imagine running two procedures side by side. Search A lists integer tuples and checks whether f equals 0.

#computability #hilbertstenth #undecidability #numbertheory
November 7, 2026 at 6:02 PM
Why Rational Solutions Change Hilbert’s Tenth Problem

An equation can have integer roots, rational-but-not-integer roots, or no rational roots at all. For x² − 4 = 0, the solutions are −2 and 2, so integers work.

#hilbertstenth #rationalnumbers #undecidability #numbertheory
November 6, 2026 at 6:02 PM
Why Defining Integers Inside Rationals Is So Hard

The equation 2x − 1 = 0 exposes the gap immediately: x = 1/2 is rational, but it is not an integer. So undecidability over integers does not automatically transfer to rational solutions.

#hilbertstenth #rationalnumbers #logic #numbertheory
November 7, 2026 at 2:02 AM
Why Finding a Root Is Easier Than Proving None Exists

A search can certify a yes answer without ever certifying a no. List integer tuples one by one and test a polynomial at each: if one makes the value 0, the search eventually finds it.

#undecidability #haltingproblem #hilbertstenth #numbertheory
November 6, 2026 at 10:02 PM
Social choice impossibility > Gödel's incompleteness > undecidability of computation > an universal best utility function can not exist > there is no best goal to have > alignment between goals can never end > open ended recursive alignment as solution
November 1, 2026 at 6:49 PM
Vesa Halava, Reino Niskanen: Diagonalization and Undecidability in Semi-Thue Systems https://arxiv.org/abs/2610.40105 https://arxiv.org/pdf/2610.40105 https://arxiv.org/html/2610.40105
October 30, 2026 at 6:43 AM
Zentrale These: Eine vollständig algorithmische Theory of Everything ist unmöglich, weil es grundlegende Grenzen dafür gibt, was formale und algorithmische Systeme entscheiden oder beweisen können. Deshalb ist auch eine vollständige Simulation des Universums unmöglich.

jhap.du.ac.ir/article_488....
Consequences of Undecidability in Physics on the Theory of Everything
General relativity treats spacetime as dynamical and exhibits its breakdown at singularities‎. ‎This failure is interpreted as evidence that quantum gravity is not a theory formulated {within} spaceti...
jhap.du.ac.ir
October 29, 2026 at 6:17 AM
Diagonalization and Undecidability in Semi-Thue Systems
**Authors:** Vesa Halava, Reino Niskanen We revisit classical diagonalization argument in the setting of semi-Thue systems, viewing computation as nondeterministic rewriting rather than sequential machine execution. Semi-Thue systems naturally generate derivation trees, making existential acceptance, reachability, and infinite derivations fundamental computational notions. We formulate acceptance and decision directly in terms of derivation trees and study the associated assertion, word, and infiniteness problems. We prove that the complements of the assertion and word problems are not recursively enumerable by direct Post-style diagonal arguments. For the infiniteness problem, we give a constructive diagonalization based on a fixed universal semi-Thue system. Unlike the classical approach, the diagonal construction is carried out entirely within the rewriting formalism: the universal system remains an ordinary nondeterministic semi-Thue system while simulating encoded semi-Thue computations, including self-reference. These results show that undecidability in semi-Thue systems arises naturally from universality and self-reference in nondeterministic rewriting, rather than from machine states or control mechanisms. This perspective clarifies the relationship between rewriting systems, recursive enumerability, and classical diagonal arguments originating in the work of Post and Turing.
arxiv.org
October 30, 2026 at 3:28 PM
Zentrale These: Eine vollständig algorithmische Theory of Everything ist unmöglich, weil es grundlegende Grenzen dafür gibt, was formale und algorithmische Systeme entscheiden oder beweisen können. Deshalb ist auch eine vollständige Simulation des Universums unmöglich.

jhap.du.ac.ir/article_488....
Consequences of Undecidability in Physics on the Theory of Everything
General relativity treats spacetime as dynamical and exhibits its breakdown at singularities‎. ‎This failure is interpreted as evidence that quantum gravity is not a theory formulated {within} spaceti...
jhap.du.ac.ir
October 29, 2026 at 6:17 AM
Yoshiki Nakamura: The Undecidability of FO3 and the Calculus of Relations with Just One Binary Relation https://arxiv.org/abs/2610.35770 https://arxiv.org/pdf/2610.35770 https://arxiv.org/html/2610.35770
October 27, 2026 at 6:42 AM
The full version of our paper is now available as part of the collection "Discrete Dynamical Modeling of Biological Systems," edited by Réka Albert, Laurence Calzone, and Claus Kadelka! 😸

#OpenAccess

www.nature.com/articles/s41...
October 19, 2026 at 3:57 PM
Jakub Michaliszyn: Undecidability of Reachability for Constraint Automata https://arxiv.org/abs/2610.15875 https://arxiv.org/pdf/2610.15875 https://arxiv.org/html/2610.15875
October 14, 2026 at 6:41 AM
that while finite may not even be provable to exist unless you operate in the correct axiomatic space.

Tbc I think the resolution to p=np is that it’s simply undecidable in zfc, and in fact its undecidability is undeciable.
October 8, 2026 at 8:04 PM
How Elliptic Curves Could Encode Integers Inside Rationals

Follow for the equations hiding behind the news.

#ellipticcurves #numbertheory #undecidability #hilbertstenth
October 7, 2026 at 9:35 PM
Excited for today’s lecture on undecidability
October 6, 2026 at 8:49 PM
OpenAI Claims Hilbert’s Tenth Problem Over Q Is Undecidable

Follow for the equations hiding behind the news.

#hilbertstenthproblem #undecidability #numbertheory #rationals
October 7, 2026 at 6:28 PM
Concentrate the injective undecidability
October 6, 2026 at 3:00 PM
Many Super Mario levels are mathematically maximally complex, containing unsolvable problems proven by MIT researchers using undecidability results.
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October 6, 2026 at 6:22 PM
Many Super Mario levels are mathematically maximally complex, containing unsolvable problems proven by MIT researchers using undecidability results.
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October 6, 2026 at 6:23 PM
Many Super Mario levels are mathematically maximally complex, containing unsolvable problems proven by MIT researchers using undecidability results.
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October 6, 2026 at 6:23 PM
Han Xiao: Non-finite Axiomatizability and Undecidability of $\mathsf{Cheq}$ https://arxiv.org/abs/2609.39577 https://arxiv.org/pdf/2609.39577 https://arxiv.org/html/2609.39577
October 1, 2026 at 6:42 AM
Thus every instance of computable undecidability is saturated also with logical undecidability, even with respect to our best aspirational foundational theories.
September 30, 2026 at 2:59 AM