Boundary Yang-Baxter equation in the RSOS/SOS representation

We construct and solve the boundary Yang-Baxter equation in the RSOS/SOS representation. We find two classes of trigonometric solutions; diagonal and non-diagonal. As a lattice model, these two classes of solutions correspond to RSOS/SOS models with fixed and free boundary spins respectively. Applied to (1+1)-dimenional quantum field theory, these solutions give the boundary scattering amplitudes of the particles. For the diagonal solution, we propose an algebraic Bethe ansatz method to diagonalize the SOS-type transfer matrix with boundary and obtain the Bethe ansatz equations.Comment: 30 pages, 5 figures, uses Latex with eepic.sty and epic.sty. Paper substantially expanded; section on SOS model is revised and a new section on the Bethe ansatz equation is adde

Doppler cooling of Ca+ ions in a Penning trap

Published versio

Associative algebraic approach to logarithmic CFT in the bulk: the continuum limit of the gl(1|1) periodic spin chain, Howe duality and the interchiral algebra

We develop in this paper the principles of an associative algebraic approach to bulk logarithmic conformal field theories (LCFTs). We concentrate on the closed $gl(1|1)$ spin-chain and its continuum limit - the $c=-2$ symplectic fermions theory - and rely on two technical companion papers, "Continuum limit and symmetries of the periodic gl(1|1) spin chain" [Nucl. Phys. B 871 (2013) 245-288] and "Bimodule structure in the periodic gl(1|1) spin chain" [Nucl. Phys. B 871 (2013) 289-329]. Our main result is that the algebra of local Hamiltonians, the Jones-Temperley-Lieb algebra JTL_N, goes over in the continuum limit to a bigger algebra than the product of the left and right Virasoro algebras. This algebra, S - which we call interchiral, mixes the left and right moving sectors, and is generated, in the symplectic fermions case, by the additional field $S(z,\bar{z})=S_{ab}\psi^a(z)\bar{\psi}^b(\bar{z})$, with a symmetric form $S_{ab}$ and conformal weights (1,1). We discuss in details how the Hilbert space of the LCFT decomposes onto representations of this algebra, and how this decomposition is related with properties of the finite spin-chain. We show that there is a complete correspondence between algebraic properties of finite periodic spin chains and the continuum limit. An important technical aspect of our analysis involves the fundamental new observation that the action of JTL_N in the $gl(1|1)$ spin chain is in fact isomorphic to an enveloping algebra of a certain Lie algebra, itself a non semi-simple version of $sp(N-2)$. The semi-simple part of JTL_N is represented by $Usp(N-2)$, providing a beautiful example of a classical Howe duality, for which we have a non semi-simple version in the full JTL image represented in the spin-chain. On the continuum side, simple modules over the interchiral algebra S are identified with "fundamental" representations of $sp(\infty)$.Comment: 69 pp., 10 figs, v2: the paper has been substantially modified - new proofs, new refs, new App C with inductive limits construction, et

Peripartum Respiratory Failure with Bilateral Pulmonary Infiltrates on Chest X-Ray

Choriocarcinoma is a gestational trophoblastic disease that carries high mortality. As this disease is highly responsive to chemotherapy, early diagnosis could lead to a favorable outcome. We report a case of metastatic pulmonary choriocarcinoma presented with hemoptysis and respiratory failure in a young woman at her third trimester. This report discusses the dilemma in deriving the diagnosis of choriocarcinoma and briefly outlines the current approaches to its treatment. Potentially life-threatening choriocarcinoma should be considered in all unusual chest radiographs of women of childbearing age. Clinicians should be aware of this possibility and proceed with the most appropriate diagnostic procedures

A Triangular Formation Strategy for Collective Behaviors of Robot Swarm

International Conference on Computational Science and Its Applications, ICCSA 2009, Seoul, 29 July-2 August 2001This paper presents, a novel decentralized control strategy, named Triangular Formation Algorithm (TFA), for a swarm of simple robots. The TFA is a local interaction strategy which basically makes three neighboring robots to form a regular triangular lattice. This strategy requires minimal conditions for robots and it can be easily realized with real robots. The TFA is executed by every member of the swarm asynchronously. For swarm obstacle avoidance, a simplified artificial physical model is introduced to work with the TFA. Simulation results showed that the global behaviors of swarm such as aggregation, flocking and obstacle avoidance in an unknown environment can be achieved using the TFA and obstacle avoidance mechanism.Department of Electrical Engineerin