Zobrazeno 1 - 10
of 41
pro vyhledávání: '"Matthew Harrison-Trainor"'
Publikováno v:
Proceedings of the American Mathematical Society. 149:3999-4013
A recent thread in computable structure theory has been the investigation of computable structures after relativizing, the key idea being that facts which are true for algebraic/structural reasons tend to relativize. On the other hand, there are path
Publikováno v:
The Journal of Symbolic Logic. 86:1706-1720
We define the Scott complexity of a countable structure to be the least complexity of a Scott sentence for that structure. This is a finer notion of complexity than Scott rank: it distinguishes between whether the simplest Scott sentence is $\Sigma _
Publikováno v:
The Journal of Symbolic Logic. 85:1664-1686
We study computable Polish spaces and Polish groups up to homeomorphism. We prove a natural effective analogy of Stone duality, and we also develop an effective definability technique which works up to homeomorphism. As an application, we show that t
Publikováno v:
The Journal of Symbolic Logic. 87:21-46
Our main result is that there exist structures which cannot be computably recovered from their tree of tuples. This implies that there are structures with no computable copies which nevertheless cannot code any information in a natural/functorial way
Publikováno v:
The Journal of Symbolic Logic. 85:972-1005
This paper investigates the principles that one must add to Boolean algebra to capture reasoning not only about intersection, union, and complementation of sets, but also about the relative size of sets. We completely axiomatize such reasoning under
Publikováno v:
Computability. 9:127-137
A computable structure $\mathcal{A}$ has degree of categoricity $\mathbf{d}$ if $\mathbf{d}$ is exactly the degree of difficulty of computing isomorphisms between isomorphic computable copies of $\mathcal{A}$. Fokina, Kalimullin, and Miller showed th
Publikováno v:
The Journal of Symbolic Logic
The Journal of Symbolic Logic, Association for Symbolic Logic, 2021, pp.1-20. ⟨10.1017/jsl.2021.58⟩
The Journal of Symbolic Logic, Association for Symbolic Logic, 2021, pp.1-20. ⟨10.1017/jsl.2021.58⟩
The $\Omega $ numbers—the halting probabilities of universal prefix-free machines—are known to be exactly the Martin-Löf random left-c.e. reals. We show that one cannot uniformly produce, from a Martin-Löf random left-c.e. real $\alpha $ , a un
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2b961baf1b147d91e7d66512e916e11a
http://arxiv.org/abs/2111.01472
http://arxiv.org/abs/2111.01472
Publikováno v:
Computability. 8:359-375
Autor:
Matthew Harrison-Trainor, Meng-Che Ho
Publikováno v:
Proceedings of the American Mathematical Society. 147:3533-3545
An abelian group A A is said to be cancellable if whenever A ⊕ G A \oplus G is isomorphic to A ⊕ H A \oplus H , G G is isomorphic to H H . We show that the index set of cancellable rank 1 torsion-free abelian groups is Π 4 0 \Pi ^0_4 m m -comple