A Simple n-Dimensional Intrinsically Universal Quantum Cellular Automaton

We describe a simple n-dimensional quantum cellular automaton (QCA) capable of simulating all others, in that the initial configuration and the forward evolution of any n-dimensional QCA can be encoded within the initial configuration of the intrinsically universal QCA. Several steps of the intrinsically universal QCA then correspond to one step of the simulated QCA. The simulation preserves the topology in the sense that each cell of the simulated QCA is encoded as a group of adjacent cells in the universal QCA.Comment: 13 pages, 7 figures. In Proceedings of the 4th International Conference on Language and Automata Theory and Applications (LATA 2010), Lecture Notes in Computer Science (LNCS). Journal version: arXiv:0907.382

The Conal representation of Quantum States and Non Trace-Preserving Quantum Operations

We represent generalized density matrices of a $d$-complex dimensional quantum system as a subcone of a real pointed cone of revolution in $\mathbb{R}^{d^2}$, or indeed a Minkowskian cone in $\mathbb{E}^{1,d^2-1}$. Generalized pure states correspond to certain future-directed light-like vectors of $\mathbb{E}^{1,d^2-1}$. This extension of the Generalized Bloch Sphere enables us to cater for non-trace-preserving quantum operations, and in particluar to view the per-outcome effects of generalized measurements. We show that these consist of the product of an orthogonal transform about the axis of the cone of revolution and a positive real linear transform. We give detailed formulae for the one qubit case and express the post-measurement states in terms of the initial state vectors and measurement vectors. We apply these results in order to find the information gain versus disturbance tradeoff in the case of two equiprobable pure states. Thus we recover Fuchs and Peres' formula in an elegant manner.Comment: 11 pages, revtex, v3: some typos correcte

Some effects of high-frequency x-rays on the oyster drill Urosalpinx cinerea

Scientists of ·the.Department of Agriculture (Bushland et al. 1955) recently announced the successful eradication of the screw-worm, Callitroga hominivorax, from the Dutch Island of Curacao. This was accomplished by releasing x-ray steralized males, which competed successfully with normal indigenous males for the females. After such matings the monogamous females deposited only sterile egg masses. Although several releases, Were necessary, eventually no fertile eggs Were detected at any of the.numerous observation points. Subsequent checks failed to reveal any live flies. Because existing information concerning ecology and reproduction of drills appeared favorable, our group was encouraged to investigate this technique as a possible control method for oyster drills. The present paper is a report; of a· series of experiments which were designed to determine the lethal dose

A Polányi-féle "kettős mozgás" : a brit és az amerikai hegemónia Belle Époque-jainak összehasonlítása

E cikk középpontjában a késő tizennyolcadik-kora tizenkilencedik század kettős mozgása (a brit hegemónia belle époque-ja és összeomlása), illetve a késő huszadik - kora tizenkilencedik század kettős mozgása (az amerikai hegemónia belle époque-ja és jelen válsága) összehasonlító elemzése áll. Az elmozdulás az állítólagosan önszabályozó piac irányába mindkét időszakban protekcionista ellenreakciókat váltott ki. Mindazonáltal jelentős különbségeket is felfedezhetünk – egyrészről a hegemón állam jellegének eltéréseiből fakadóan, másrészt abban, hogy az alárendelt erők a késő huszadik században jóval nagyobb szerepet játszottak abban, hogy elmozdulás történjen a piaci önszabályozás irányába