Sökning: "category"
Visar resultat 11 - 15 av 953 avhandlingar innehållade ordet category.
11. Ultrapowers as sheaves on a category of ultrafilters
Sammanfattning : .... LÄS MER
12. N-complexes and Categorification
Sammanfattning : This thesis consists of three papers about N-complexes and their uses in categorification. N-complexes are generalizations of chain complexes having a differential d satisfying dN = 0 rather than d2 = 0. Categorification is the process of finding a higher category analog of a given mathematical structure. LÄS MER
13. Representation theorems for abelian and model categories
Sammanfattning : In this PhD thesis we investigate a representation theorem for small abelian categories and a representation theorem for left proper, enriched model categories, with the purpose of describing them concretely in terms of specific well-known categories.For the abelian case, we study the constructivity issues of the Freyd-Mitchell Embedding Theorem, which states the existence of a full embedding from a small abelian category into the category of modules over an appropriate ring. LÄS MER
14. Structure and representations of certain classes of infinite-dimensional algebras
Sammanfattning : We study several infinite-dimensional algebras and their representation theory. In Paper I, we study the category O for the (centrally extended) Schrödinger Lie algebra, which is an analogue of the classical BGG category O. We decompose the category into a direct sum of "blocks", and describe Gabriel quivers of these blocks. LÄS MER
15. Semigroups, multisemigroups and representations
Sammanfattning : This thesis consists of four papers about the intersection between semigroup theory, category theory and representation theory. We say that a representation of a semigroup by a matrix semigroup is effective if it is injective and define the effective dimension of a semigroup S as the minimal n such that S has an effective representation by square matrices of size n. LÄS MER
