Typing actors using behavioural types

The actor model of computation assists and disciplines the development of concurrent programs by forcing the software engineer to reason about high-level concurrency abstractions. While this leads to a better handling of concurrency-related issues, the model itself does not exclude erratic program behaviours. In this paper we consider the actor model and investigate a type-based static analysis to identify actor systems which may behave erraticly during runtime. We consider the notion of behavioural types and consider issues related to the nature of the actor model including non-determinism, multi-party communication, dynamic actor spawning, non-finite computation and a possibly changing communication topology, which we contrast with existing works.peer-reviewe

Post hoc verification of quantum computation

With recent progress on experimental quantum information processing, an important question has arisen as to whether it is possible to verify arbitrary computation performed on a quantum processor. A number of protocols have been proposed to achieve this goal, however all are interactive in nature, requiring that the computation be performed in an interactive manner with back and forth communication between the verifier and one or more provers. Here we propose two methods for verifying quantum computation in a non-interactive manner based on recent progress in the understanding of the local Hamiltonian problem. Provided that the provers compute certain witnesses for the computation, this allows the result of a quantum computation to be verified after the fact, a property not seen in current verification protocols.Comment: 4 pages, 2 figure

Reusability of coordination programs

Isolating computation and communication concerns into separate pure computation and pure coordination modules enhances modularity, understandability, and reusability of parallel and/or distributed software. This can be achieved by moving communication primitives (such as SendMessage and ReceiveMessage), which are now commonly scattered in application codes, into separate modules written in a language dedicated to the coordination of processes and the flow of information among them. MANIFOLD is a pure coordination language that encourages the separation of communication and computation concerns, We use real, concrete, running MANIFOLD programs to demonstrate the concept of pure coordination modules and the advantage of their reuse in applications of different nature