S. G. Simpson

activity

20132021

most citedSymbolic dynamics: entropy = dimension = complexity

2 citations · 2 across the 9 of their papers we have counts for

collaborators

Showing 2021Show all

3 papers · 1 filter

math.LO2021

Pseudojump inversion in special r. b. $Π_{1}^{0}$ classes

Hayden R. Jananthan, Stephen G. Simpson

The Jump Inversion Theorem says that for every real $A \geq_{T} 0^{'}$ there is a real $B$ such that $A \equiv_{T} B^{'} \equiv_{T} B \oplus 0^{'}$ . A known refinement of this theorem says that we…

math.LO2021

Very weak fragments of weak Kőnig's lemma

Stephen G. Simpson, Keita Yokoyama

It is well-known that any finite $Π_{1}^{0}$ -class of $2^{N}$ has a computable member. Then, how can we understand this in the context of reverse mathematics? In this note,…

math.LO2021

Turing Degrees of Hyperjumps

Hayden R. Jananthan, Stephen G. Simpson

The Posner-Robinson Theorem states that for any reals $Z$ and $A$ such that $Z \oplus 0^{'} \leq_{T} A$ and $0 <_{T} Z$ , there exists $B$ such that $A \equiv_\mathrm{T}…

Pseudojump inversion in special r. b. Π10​ classes

Very weak fragments of weak Kőnig's lemma

Turing Degrees of Hyperjumps

Pseudojump inversion in special r. b. $Π_{1}^{0}$ classes