On fillable contact structures up to homotopy

Let be a closed, oriented -manifold. The set of homotopy classes of positive, fillable contact structures on is a subtle invariant of , known to always be a finite set. In this paper we study under the assumption that carries metrics with positive scalar curvature. Using Seiberg-Witten gauge theory, we prove that two positive, fillable contact structures on are homotopic if and only if they are homotopic on the complement of a point. This implies that the cardinality of is bounded above by the order of the torsion subgroup of . Using explicit examples we show that without the geometric assumption on such a bound can be arbitrarily far from holding.

     

On the Evaluation of the Evolution Operator Z Reg( R 2, R 1) in the Diakonov–Petrov Approach to the Wilson Loop

We evaluate the evolution operator Z _Reg(R ₂,R ₁) introduced by Diakonov and Petrov for the definition of the Wilson loop in terms of a path integral over gauge degrees of freedom. We use the procedure suggested by Diakonov and Petrov (Physics Letters B 224 (1989) 131) and show that the evolution operator vanishes. PACS numbers: 11.10.-z; 11.15.-q; 12.38.-t; 12.38.Aw; 12.90.+b.     

Non-locality and Gauge Freedom in Deutsch and Hayden’s Formulation of Quantum Mechanics

Deutsch and Hayden have proposed an alternative formulation of quantum mechanics which is completely local. We argue that their proposal must be understood as having a form of ‘gauge freedom’ according to which mathematically distinct states are physically equivalent. Once this gauge freedom is taken into account, their formulation is no longer local.      

Independence of Yang-Mills Equations with Respect to the Invariant Pairing in the Lie Algebra

It is proved that the Euler–Lagrange equations of a Yang-Mills type Lagragian is independent with respect to the chosen pairing in the Lie algebra. Moreover, the Hamilton-Cartan equations of these Lagrangians are obtained and proved to be also independent with respect to the pairing. PACS Numbers 2003: 02.20.Qs, 02.20.Sv, 02.20.Tw, 02.40.Ma, 02.40.Vh, 11.10.Ef, 11.15.Kc Mathematics Subject Classification 2000: Primary 70S15, Secondary 58A20, 58E15, 58E30, 70S05, 70S10, 81T13     

Infrared gluon and ghost propagators from lattice QCD

We report on the infrared limit of the quenched lattice Landau gauge gluon and ghost propagators as well as the strong-coupling constant computed from large asymmetric lattices. The infrared lattice propagators are compared with the pure power law solutions from Dyson-Schwinger equations (DSE). For the gluon propagator, the lattice data is compatible with the DSE solution. The preferred measured gluon exponent being ∼0.52, favouring a vanishing propagator at zero momentum. The lattice ghost propagator shows finite-volume effects and, for the volumes considered, the propagator does not follow a pure power law. Furthermore, the strong-coupling constant is computed and its infrared behaviour investigated.     

电阻应变测量技术在压力容器检验中的应用

介绍了电阻应变测量技术的测试原理和测试方法，并结合化工企业对压力容器检验的技术要求，应用电阻应变测量技术对典型压力容器作出了应力分析和安全评定。     

法坐标系的性质及应用一例

论述了在Ｐｏｉｎｃａｒｅ规范场论中选用径向规范条件等价于选择法坐标系，证明了法坐标系中的局部活动标架沿着从原点开始的自平行线构成平行矢量场，给出了一般坐标与法坐标之间的变换关系，再利用这个关系在法坐标系中微扰计算了联络场的一重积分对量子Ｗｉｌｓｏｎ圈的贡献。     

Recent advances in lattice gauge theories

Recent progress in the field of lattice gauge theories is briefly reviewed for a nonspecialist audience. While the emphasis is on the latest and more definitive results that have emerged prior to this symposium, an effort has been made to provide them with minimal technicalities.     

2+1维SU(2)格点规范场胶球波函数的高阶RPA计算

采用无规相近似(RPA)耦合集团展开方法求解薛定谔本征值方程，计算高阶胶球波函数. 在计算中，用空心Wilson圈图作为试探波函数，对特殊Wilson圈图作近似处理，计算出的2+1维SU(2)格点规范场的六阶和七阶胶球波函数的μ0F和μ2F及相关参数z 在弱耦合区(β=4.8-9.6)出现较好的标度行为，七阶真空能量在整个区域(β=0.8-8.0)与六阶真空能量一致.