Abstract. Let L be a lattice and M a bounded distributive lattice. Let ConL denote the congruence lattice of L, P (M) the Priestley dual space of M , and L (M) the lattice of continuous order-preserving maps from P (M) to L with the discrete topology. It is shown that Con(L ) ∼= (ConL) P (ConM) Λ , the lattice of continuous order-preserving maps from P (ConM) to ConL with the Lawson topology. V...

Let A⊆B be a ring extension and G set of A-submodules B. We introduce class closure operations on (which we call multiplicative (A,B,G)) that generalizes the classes star, semistar semiprime operations. study how Mult(A,B,G) these varies when A, B or vary, behaves under homomorphisms. As an application, show to reduce star analytically unramified one-dimensional Noetherian domains closures fini...

We bring a linkage from representation theory of Lie groups to homotpy theory for maps between flag manifolds. As applications we derive from representation theory abundant families of homotopy classes of maps between flag manifolds whose induced cohomology homomorphisms can be read from the characters of the representations. 2000 Mathematical Subject Classification: 14F35 (22E46, 57R22).

Adviser: Carina Curto Neurons in the brain represent external stimuli via neural codes. These codes often arise from stimulus-response maps, associating to each neuron a convex receptive field. An important problem confronted by the brain is to infer properties of a represented stimulus space without knowledge of the receptive fields, using only the intrinsic structure of the neural code. How d...