Operator-Schmidt decomposition of the quantum Fourier transform on C^N1 tensor C^N2

Operator-Schmidt decompositions of the quantum Fourier transform on C^N1 tensor C^N2 are computed for all N1, N2 > 1. The decomposition is shown to be completely degenerate when N1 is a factor of N2 and when N1>N2. The first known special case, N1=N2=2^n, was computed by Nielsen in his study of the communication cost of computing the quantum Fourier transform of a collection of qubits equally distributed between two parties. [M. A. Nielsen, PhD Thesis, University of New Mexico (1998), Chapter 6, arXiv:quant-ph/0011036.] More generally, the special case N1=2^n1<2^n2=N2 was computed by Nielsen et. al. in their study of strength measures of quantum operations. [M.A. Nielsen et. al, (accepted for publication in Phys Rev A); arXiv:quant-ph/0208077.] Given the Schmidt decompositions presented here, it follows that in all cases the communication cost of exact computation of the quantum Fourier transform is maximal.Comment: 9 pages, LaTeX 2e; No changes in results. References and acknowledgments added. Changes in presentation added to satisfy referees: expanded introduction, inclusion of ommitted algebraic steps in the appendix, addition of clarifying footnote

The World of Moths. Michael Dickens and Eric Storey. Macmillan Publishing Co., Inc., New York, 1974. 128 p., 103 plates. $6.95.

(excerpt) This little book will undoubtedly please the amateur collector and rearer of the exotically and exquisitely colored species such as found in the Saturniidae and Sphing- idae. Of the 103 colored photographic plates, 69 illustrate species from these two popular families. Each species is figured on a white background in sharp and vivid color. One species is figured on a page, except for Epicopeia polydora, which includes a figure of its mimetic model Papilio rhetenor

Butterflies of the Rocky Mountain States. Edited by Clifford D. Ferris and F. Martin Brown. University of Oklahoma Press, Norman. 464 pages, incl. 4 color plates. 1981. 35.00(cloth),35.00 (cloth), 15.95 (paper).

(excerpt) The long awaited guide to the butterflies of the Rocky Mountains will be received with great delight by many lepidopterists who collect butterflies in this rugged and beautiful region

Continuity bounds for entanglement

This note quantifies the continuity properties of entanglement: how much does entanglement vary if we change the entangled quantum state just a little? This question is studied for the pure state entanglement of a bipartite system and for the entanglement of formation of a bipartite system in a mixed state.Comment: 5 pages, submitted to Physical Review A Brief Reports. Minor typo in equation (25) corrected in resubmissio

DsJD_{sJ}(2317) meson production at RHIC

Production of $D_{sJ}$(2317) mesons in relativistic heavy ion collisions at RHIC is studied. Using the quark coalescence model, we first determine the initial number of $D_{sJ}$(2317) mesons produced during hadronization of created quark-gluon plasma. The predicted $D_{sJ}$(2317) abundance depends sensitively on the quark structure of the $D_{sJ}$(2317) meson. An order-of-magnitude larger yield is obtained for a conventional two-quark than for an exotic four-quark $D_{sJ}$(2317) meson. To include the hadronic effect on the $D_{sJ}$(2317) meson yield, we have evaluated the absorption cross sections of the $D_{sJ}$(2317) meson by pion, rho, anti-kaon, and vector anti-kaon in a phenomenological hadronic model. Taking into consideration the absorption and production of $D_{sJ}$(2317) mesons during the hadronic stage of heavy ion collisions via a kinetic model, we find that the final yield of $D_{sJ}$(2317) mesons remains sensitive to its initial number produced from the quark-gluon plasma, providing thus the possibility of studying the quark structure of the $D_{sJ}$(2317) meson and its production mechanism in relativistic heavy ion collisions.Comment: 12 pages, 6 figure

Radiative decay of the X(3872) as a mixed molecule-charmonium state in QCD Sum Rules

We use QCD sum rules to calculate the width of the radiative decay of the meson X(3872), assumed to be a mixture between charmonium and exotic molecular $[c\bar{q}][q\bar{c}]$ states with $J^{PC}=1^{++}$. We find that in a small range for the values of the mixing angle, $5^0\leq\theta\leq13^0$, we get the branching ratio $\Gamma(X\to J/\psi\gamma)/\Gamma(X\to J/\psi\pi^+\pi^-)=0.19\pm0.13$, which is in agreement, with the experimental value. This result is compatible with the analysis of the mass and decay width of the mode $J/\psi(n\pi)$ performed in the same approach.Comment: 7 pages, 9 figures; revised version accepted for publication in Phys. Rev.

A Formal Model for Trust in Dynamic Networks

We propose a formal model of trust informed by the Global Computing scenario and focusing on the aspects of trust formation, evolution, and propagation. The model is based on a novel notion of trust structures which, building on concepts from trust management and domain theory, feature at the same time a trust and an information partial order

Petri Nets and Other Models of Concurrency

This paper retraces, collects, and summarises contributions of the authors --- in collaboration with others --- on the theme of Petri nets and their categorical relationships to other models of concurrency