We show that unitarity does not allow cloning of any two points in a ray. This has implication for cloning of the geometric phase information in a quantum state. In particular, the quantum history which is encoded in the geometric phase during cyclic evolution of a quantum system cannot be copied. We also prove that the generalized geometric phase information cannot be copied by a unitary opera...

In this paper we consider three potential simplifications to a result of Solovay’s concerning the Turing degrees of nonstandard models of arbitrary completions of first-order Peano Arithmetic (PA). Solovay characterized the degrees of nonstandard models of completions T of PA, showing that they are the degrees of sets X such that there is an enumeration R ≤T X of an “appropriate” Scott set and ...

The background to these notes is the expectation that mathematical modelling and simulation is going to play increasingly important role in the understanding of the organization and control of genetic-, metabolic-, and signalling pathways. I am going to argue that for modelling and simulation to help our understanding of cellular dynamics, the current practice of experimental design has to chan...

the problem of mental causation was one of the most important problems in philosophy of mind at least from the time of descartes. since cartesian philosophers found the causal interaction of the soul and the body problematic, they explained away the direct relation between the soul and the body in different ways. however, the problem was not resolved in contemporary philosophy of mind when the ...

1. Singular vs. general causation In many people, caffeine causes slight muscle tremors, particularly in their hands. In general, the Caffeine → Muscle Tremors causal connection is a noisy one: someone can drink coffee and experience no hand shaking, and there are many other factors that can lead to muscle tremors. Now suppose that Jane drinks several cups of coffee and then notices that her ha...

We investigate expressiveness of a fragment of the ambient calculus, a formalism for describing distributed and mobile computations. More precisely, we study expressiveness of the pure and public ambient calculus from which the capability has been removed, in terms of the reachability problem of the reduction relation. Surprisingly, we show that even for this very restricted fragment, the reach...