List questions from topos-theory

Published on 26 Mar 2026 - 3:12

621

Views

Are abelian groups in a [elementary] topos $\mathcal E$ an abelian subcat of $\mathcal E$?

Published on 22 Jan 2012 - 17:57

1.2k

Views

Importance of 'smallness' in a category, and functor categories

Published on 04 Feb 2012 - 19:10

1.1k

Views

How to find exponential objects and subobject classifiers in a given category

Published on 06 Feb 2012 - 2:50

121

Views

Is $(f_A)\times B\to f_(A\times f^*B)$ an iso in a elementary topos?

Published on 16 Feb 2012 - 18:05

205

Views

Does a geometric morphism $f\colon \cal E\to F$ preserves and reflects the subobject classifier?

Published on 27 Feb 2012 - 20:08

1.4k

Views

Example of a small topos

Published on 03 Mar 2012 - 17:26

592

Views

An example of a Grothendieck topology

Published on 25 Mar 2026 - 17:22

263

Views

Does the restriction functor (big to small) commute with the inverse functor?

Published on 17 Mar 2012 - 21:21

368

Views

Why are injective $\mathscr{O}$-modules flasque?

Published on 31 Mar 2012 - 16:33

402

Views

Exercise from Leinster's Informal introduction to topos theory

Published on 02 Apr 2012 - 10:51

219

Views

How to get a geometric morphism out of a section? (And general pedagogy on classifying toposes)

Published on 29 Apr 2012 - 22:41

8.4k

Views

What is Mazzola's "Topos of Music" about?

Published on 23 Feb 2026 - 11:40

313

Views

Counterexample for a pullback-pushout situation

Published on 14 May 2012 - 7:07

172

Views

Composing covers with epis

Published on 16 May 2012 - 14:56

List Question

What are the algebras of the double powerset monad?

Are abelian groups in a [elementary] topos $\mathcal E$ an abelian subcat of $\mathcal E$?

Importance of 'smallness' in a category, and functor categories

How to find exponential objects and subobject classifiers in a given category

Is $(f_A)\times B\to f_(A\times f^*B)$ an iso in a elementary topos?

Does a geometric morphism $f\colon \cal E\to F$ preserves and reflects the subobject classifier?

Example of a small topos

An example of a Grothendieck topology

Does the restriction functor (big to small) commute with the inverse functor?

Why are injective $\mathscr{O}$-modules flasque?

Exercise from Leinster's Informal introduction to topos theory

How to get a geometric morphism out of a section? (And general pedagogy on classifying toposes)

What is Mazzola's "Topos of Music" about?

Counterexample for a pullback-pushout situation

Composing covers with epis

Trending Questions

Popular # Hahtags

Popular Questions