Results 21 to 30 of about 687,146 (243)
Galois theory and theaters of action in a topos
Journal of Pure and Applied Algebra, 1980 Constructing a Galois theory for geometric fields in a topos presents certain difficulties. If K E F is a Galoisian field extension in a topos 5Z, then one can construct the internal group of K-automorphisms of F but it might be trivial even when K f F (see Example 6.6).
John F. Kennison
openalex +3 more sources
The Sierpinski Object in the Scott Realizability Topos [PDF]
Logical Methods in Computer Science, 2020 We study the Sierpinski object $\Sigma$ in the realizability topos based on Scott's graph model of the $\lambda$-calculus. Our starting observation is that the object of realizers in this topos is the exponential $\Sigma ^N$, where $N$ is the natural ...
Tom de Jong, Jaap van Oosten
doaj +1 more source
Gelfand spectra in Grothendieck toposes using geometric mathematics [PDF]
Electronic Proceedings in Theoretical Computer Science, 2014 In the (covariant) topos approach to quantum theory by Heunen, Landsman and Spitters, one associates to each unital C*-algebra, A, a topos T(A) of sheaves on a locale and a commutative C*-algebra, a, within that topos.
Bas Spitters +2 more
doaj +1 more source
Point-free Construction of Real Exponentiation [PDF]
Logical Methods in Computer Science, 2022 We define a point-free construction of real exponentiation and logarithms, i.e.\ we construct the maps $\exp\colon (0, \infty)\times \mathbb{R} \rightarrow \!(0,\infty),\, (x, \zeta) \mapsto x^\zeta$ and $\log\colon (1,\infty)\times (0, \infty ...
Ming Ng, Steven Vickers
doaj +1 more source
A Topos for Algebraic Quantum Theory [PDF]
Communications in Mathematical Physics, 2009 The aim of this paper is to relate algebraic quantum mechanics to topos theory, so as to construct new foundations for quantum logic and quantum spaces. Motivated by Bohr's idea that the empirical content of quantum physics is accessible only through classical physics, we show how a C*-algebra of observables A induces a topos T(A) in which the ...
Heunen, Chris +2 more
openaire +6 more sources
On the Nielsen-Schreier Theorem in Homotopy Type Theory [PDF]
Logical Methods in Computer Science, 2022 We give a formulation of the Nielsen-Schreier theorem (subgroups of free groups are free) in homotopy type theory using the presentation of groups as pointed connected 1-truncated types.
Andrew W Swan
doaj +1 more source
Politics of evidence: Think tanks and the Academies Act
British Educational Research Journal, Volume 48, Issue 6, Page 1232-1253, December 2022., 2022 Abstract Previous research has identified political ideology as central in the landmark Academies Act (2010). This article further analyses how politics of evidence played its part in the policy process by focusing on long‐term structural changes and preferences among policymakers. The article draws on policymaker interviews after the reform, a mapping
Jaakko Kauko
wiley +1 more source
On the Structure of Abstract H*-Algebras [PDF]
Electronic Proceedings in Theoretical Computer Science, 2018 Previously we have shown that the topos approach to quantum theory of Doering and Isham can be generalised to a class of categories typically studied within the monoidal approach to quantum theory of Abramsky and Coecke.
Kevin Dunne
doaj +1 more source
Navigating value networks to co‐create sustainable business models: An actionable staging approach
Business Strategy and the Environment, Volume 32, Issue 1, Page 240-258, January 2023., 2023 Abstract Sustainable transitions typically require collaboration between multiple actors in the value chain or value network. Recent research has emphasized mapping of stakeholders and values as a starting point for identifying opportunities to realign these relationships, followed by business model experimentation to enable change.
Signe Pedersen +2 more
wiley +1 more source