Following a proposal of Humberstone, this paper studies a semantics for modal logic based on partial “possibilities” rather than total “worlds.” There are a number of reasons, philosophical and mathematical, to find this alternative semantics attractive. Here we focus on the construction of possibility models with a finitary flavor. Our main completeness result shows that for a number of standa...

We prove essential self-adjointness of the spatial part linear Klein-Gordon operator with external potential for a large class globally hyperbolic manifolds. The proof is conducted by fusion new results concerning manifolds, theory weighted Hilbert spaces and related functional analytic advances.

We introduce a novel approach for defining a δ′-interaction on a subset of the real line of Lebesgue measure zero which is based on Sturm– Liouville differential expression with measure coefficients. This enables us to establish basic spectral properties (e.g., self-adjointness, lower semiboundedness and spectral asymptotics) of Hamiltonians with δ′-interactions concentrated on sets of complica...

In this article, we mainly study the weighted composition-differentiation operator on Bergman space A?2 and derivative Hardy S12, which characterize complex symmetric Du,?. Moreover, normality self-adjointness of Du,? are also discussed.

We extend the recently developed kinematical framework for diffeomorphism invariant theories of connections for compact gauge groups to the case of a diffeomorphism invariant quantum field theory which includes besides connections also fermions and Higgs fields. This framework is appropriate for coupling matter to quantum gravity. The presence of diffeomorphism invariance forces us to choose a ...