6533b85efe1ef96bd12c09d3

RESEARCH PRODUCT

Lawvere–Tierney sheaves in Algebraic Set Theory

Steve AwodeyPeter Lefanu LumsdaineMichael A. WarrenNicola Gambino

subject

Algebraic setPure mathematicsLogicMathematics - Category TheoryMathematics - LogicTopos theoryPhilosophyMathematics::LogicMathematics::Algebraic GeometryMathematics::Category TheoryFOS: MathematicsCategory Theory (math.CT)Algebraic Set Theory sheavesLogic (math.LO)03C90 03G30 03F50AxiomMathematics

description

We present a solution to the problem of defining a counterpart in Algebraic Set Theory of the construction of internal sheaves in Topos Theory. Our approach is general in that we consider sheaves as determined by Lawvere-Tierney coverages, rather than by Grothendieck coverages, and assume only a weakening of the axioms for small maps originally introduced by Joyal and Moerdijk, thus subsuming the existing topos-theoretic results.

https://eprints.whiterose.ac.uk/113167/1/0711.1529.pdf