the paper sets forth in detail categorically-algebraic or catalg foundations for the operations of taking the image and preimage of (fuzzy) sets called forward and backward powerset operators. motivated by an open question of s. e. rodabaugh, we construct a monad on the category of sets, the algebras of which generate the fixed-basis forward powerset operator of l. a. zadeh. on the next step, w...

We develop a natural generalization of vector-valued frame theory, which we term operator-valued frame theory, using operator-algebraic methods. This extends work of the second author and D. Han which can be viewed as the multiplicity one case and extends to higher multiplicity their dilation approach. We prove several results for operator-valued frames concerning duality, disjointedness, compl...

The main theorems below are Theorem 9 and Theorem 11. As far as I know, Theorem 9 represents a slight improvement over what currently appears in the literature, and gives a fairly easy proof of Theorem 11 which is due to R. Howe and C. Moore [4]. In the semisimple case, the Howe-Moore result follows from [6] or [7]. The proofs appearing here are relatively elementary and some readers will recog...

For a finite positive Borel measure μ on the unit circle, let D(μ) be associated harmonically weighted Dirichlet space. A shift invariant subspace M recognizes strong approximate spectral cosynthesis if there exists sequence of subspaces M_k, with codimension, such that orthogonal projections onto M_k converge in operator topology to projection M. If is sum atoms, then we show admits cosynthesis.

On $(X,\omega)$ compact K\"ahler manifold, given a model type envelope $\psi\in PSH(X,\omega)$ (i.e. singularity type) we prove that the Monge-Amp\`ere operator is an homeomorphism between set of $\psi$-relative finite energy potentials and measures endowed with their strong topologies as coarsest refinements weak such relative energies become continuous. Moreover, totally ordered family $\math...