Paper detail

Subtoposes of the Effective Topos

We seek progress in the study of subtoposes of the effective topos. First we treat Van Oosten's result that local operators on the effective topos are internally NNO-indexed joins of what we shall call 'basic' local operators. Our main innovation is the notion of a tree-like structure called 'sight', which provides a tangible representation of local operators on the effective topos. This leads in particular to the establishment of an infinity of new basic subtoposes of the effective topos. Various comparisons (inequalities and non-inequalities) in between these new examples and known examples such as Turing degrees are made. Sights also provide a realizability-like semantics for the first-order arithmetic of subtoposes of the effective topos. The text begins with an overview of relevant tripos theory and some topos-theoretic constructions of local operators.

preprint2011arXivOpen access

Signal facts

What is known right now

Open access1 author3 topics

Next steps

Decide what to do with this paper

Use like or dislike for the fast social read. The more specific scholarly feedback stays available below when needed.

Log in to curate

Reading frame

Keep the important context close to the paper

Keep the important signals around this paper in one place: votes, save state, collection context, reviews and the metadata you need before deciding what to do next.

Authors

Institutions

Add specific reaction

Move through the context

Research map

Open full explorer

Move through nearby people, institutions, topics and adjacent work without leaving the paper page.

Building this map preview

BZPEER is loading the nearby papers, people, topics and institutions for this page.

Structured reviews

0 review(s)

ContributeLeave structured feedbackUse the review template when you have a concrete strength, concern or method question.Open review form

No structured reviews yet. High-signal critique starts here.

Work discussion

0 comment(s)

DiscussAdd a high-signal commentKeep quick notes, caveats and replication pointers separate from formal reviews.Open comment form

No discussion yet. The first strong comment sets the tone.