Anomaly and Nonplanar Diagrams in Noncommutative Gauge Theories

Anomalies arising from nonplanar triangle diagrams of noncommutative gauge theory are studied. Local chiral gauge anomalies for both noncommutative U(1) and U(N) gauge theories with adjoint matter fields are shown to vanish. For noncommutative QED with fundamental matters, due to UV/IR mixing a finite anomaly emerges from the nonplanar contributions. It involves a generalized $\star$-product of gauge fields.Comment: 28 pages, Latex, axodraw.sty; v2: version to appear in Int. J. Mod. Phys. A. (2001

Vacuum structure of bifundamental gauge theories at finite topological angles

We discuss possible vacuum structures of $SU(n)\times SU(n)$ gauge theories with bifundamental matters at finite $\theta$ angles. In order to give a precise constraint, a mixed 't Hooft anomaly is studied in detail by gauging the center $\mathbb{Z}_n$ one-form symmetry of the bifundamental gauge theory. We propose phase diagrams that are consistent with the constraints, and also give a heuristic explanation of the result based on the dual superconductor scenario of confinement.Comment: 28 pages, 6 figures; (v2) references adde

Molecular dynamics simulation for baryon-quark phase transition at finite temperature and density

We study the baryon-quark phase transition in a molecular dynamics (MD) of quark degrees of freedom at finite temperature and density. The baryon state at low density and temperature, and the deconfined quark state at high density and temperature are reproduced. We investigate the equations of state of matters with different $u$-$d$-$s$ compositions. Then we draw phase diagrams in the temperature-density plane by this simulation. It is found that the baryon-quark transition is sensitive to the quark width.Comment: submitted to EPJ

Network Coherence Time Matters - Aligned Image Sets and the Degrees of Freedom of Interference Networks with Finite Precision CSIT and Perfect CSIR

This work obtains the first bound that is provably sensitive to network coherence time, i.e., coherence time in an interference network where all channels experience the same coherence patterns. This is accomplished by a novel adaptation of the aligned image sets bound, and settles various open problems noted previously by Naderi and Avestimehr and by Gou et al. For example, a necessary and sufficient condition is obtained for the optimality of 1/2 DoF per user in a partially connected interference network where the channel state information at the receivers (CSIR) is perfect, the channel state information at the transmitters (CSIT) is instantaneous but limited to finite precision, and the network coherence time is T_c= 1. The surprising insight that emerges is that even with perfect CSIR and instantaneous finite precision CSIT, network coherence time matters, i.e., it has a DoF impact.Comment: 19 pages, 4 figure

Barriers to the effective use of finite element analysis in industry

This workshop represents the first step in a comprehensive and wideranging pan-European information gathering exercise on a topic that is at the heart of the FENET project. The following three categories of industrial organisation have been identified and all have a valuable input to the workshop. The FENET world-wide survey, which sought to establish the significance of barriers to the effective use of finite element analysis across a range of industry sectors, including Aerospace, Land Transport, Biomedical, Civil Construction, Consumer Goods, Marine and Offshore, Power and Pressure Systems and Process & Manufacture, ran from November 2002 - July 2003. The survey, consisting of over 450 questions, included a wide range of issues covering education and awareness, the staffing of FE projects, the cost of FE products; support-related matters in the widest sense, and an extensive list of functionality-related matters, including integration of the analysis function. Particular emphasis was placed on the topics of multi-physics & analysis technology, life extension & durability and product & system optimization, as these are identified themes within the FENet project