Asymptotic structure near event horizon and Cardy-Verlinde formula for general asymptotically flat stationary black hole

The asymptotically anti-de Sitter structure near event horizon of general asymptotically flat stationary black hole is found, and the Cardy-Verlinde formula is generalized to the asymptotically flat black holes in the Einstein-Maxwell theory and low-energy effective field theory describing string. The result that the entropy of conformal field theory (CFT) agrees precisely with black-hole entropy provides a CFT interpretation of the Bekenstein-Hawking entropy of the asymptotically flat stationary black holes.     

On Rosen's bi-metric theory of gravitation

The field equations of Rosen's bi-metric theory of gravitation [1] are solved exactly. The solutions are the same as in the author's theory of gravitation [2]. These solutions are, however, incompatible with Rosen's conservation laws and his second (flat) metric. Incompatibility with the conservation laws arises in second order. Incompatibility with the flat metric arises in first order but only for time-dependent fields. Rosen's theory is defensible only as a static first order theory and predicts the red shift light deflection and time-delay correctly.     

Twistor theory: An approach to the quantisation of fields and space-time

Twistor theory offers a new approach, starting with conformally-invariant concepts, to the synthesis of quantum theory and relativity. Twistors for flat space-time are the SU(2,2) spinors of the twofold covering group O(2,4) of the conformal group. They describe the momentum and angular momentum structre of zero-rest-mass particles. Space-time points arise as secondary concepts corresponding to linear sets in twistor space. They, rather than the null cones, should become “smeared out” on passage to a quantised gravitational theory. Twistors are represented here in two-component spinor terms. Zero-rest-mass fields are described by holomorphic functions on twistor space, on which there is a natural canonical structure leading to a natural choice of canonical quantum operators. The generalisation to curved space can be accomplished in three ways; i) local twistors, a conformally invariant calculus, ii) global twistors, and iii) asymptotic twistors which provide the framework for an S-matrix approach in asymptotically flat space-times. A Hamiltonian scattering theory of global twistors is used to calculate scattering cross-sections. This leads to twistor analogues of Feynman graphs for the treatment of massless quantum electrodynamics. The recent development of methods for dealing with massive (conformal symmetry breaking) sources and fields is briefly reviewed.     

Remarks on (0,2) models and intermediate scale scenarios in string theory

Problems associated with large intermediate scales in string theory are discussed. It is shown that, in σ-model perturbation theory, the superpotential of theories with (2,2) supersymmetry is purely cubic. As a result, to exhibit flat directions with (0,2) supersymmetry, one needs to study only a small number of Yukawa couplings. Usually these flat directions are lifted by nonperturbative effects in the σ model. Examples where this is not the case, due to Cvetic and to Distler and Greene, are discussed. It is shown that in the former case, there are not, generically, extra massless particles to play the role of Higgs fields. The problems of proton decay, neutrino masses, and obtaining light Higgs fields in models with large intermediate scales are considered, and various difficulties with existing proposals are pointed out.     

Instability of flat spacetime in semiclassical gravity

The semiclassical theory of gravity is considered in which an asymptotically flat background metric is coupled to quantized matter. We show that, in general, there are modes with spacelike wave vectors for small metric fluctuations around flat spacetime. Besides the usual axioms of quantum field theory in flat spacetime, the proof rests on the existence of a hard trace anomaly in the energy-momentum tensor due to matter self-couplings. Two possible interpretations of the result are discussed.     

Nonlinear surface waves in a symmetrical three-layer structure caused by the generation of excitons and biexcitons in semiconductors

A theory of nonlinear TE-polarized surface waves propagating along the flat interfaces of a symmetric flat three-layer structure with a linear core and nonlinear coatings is developed. The coatings are nonlinear due to the optical exciton-biexciton conversion. The dispersion laws of the propagating waves are found and analyzed.     

Image resolution and the properties of optical-wave target detection and imaging by using the NR-PC flat lens

We used the method of two-dimensional (2D) finite-difference time-domain (FDTD) to study the characteristics of optical-wave target detection and imaging from negative-refraction photonic crystal (NR-PC) flat lens in the paper. The theory of image resolution was introduced. The results show that there exists a transmission peak, with a value far greater than unit, resulting from the influence of the mini-forbidden bands and resonance excitation effect at resonance frequency. And, the refocusing of backscattered optical wave from the target leads to its image with a sub-wavelength lateral resolution and great amplitude as long as the target is placed at the focus of the NR-PC flat lens. And the application of NR-PC flat lens can be extended in optical area, especially in the detection and imaging of small target.     

Transverse magnetic wave propagation along flat biological membranes

Propagation of the transverse magnetic waves along flat biological membranes are studied within the framework of the classical electrodynamics. The ionic excitations adjacent to the exterior and interior surfaces of the flat cell membranes are modeled by a quasi two-dimensional (2D) layers of counter-ions fluid which is described by means of the linearized hydrodynamic theory. Dispersion relation of the plasma wave in the system is obtained by solving Maxwell and fluid equations with appropriate boundary conditions.     

基于多次平移的平面绝对检测仿真

将待测面形表示为多项式的和,通过分别沿x,y向多次平移待检光学元件得到移动前后待测元件面形差,采用最小二乘法拟合多项式系数,得到待检光学元件的绝对面形。推导了多次平移法的理论公式,并进行了仿真实验,模拟了移动次数、移动间隔和采样点数对测量精度的影响。仿真结果表明:待测平面与初始平面残差图的均方根值为5.118×10~(-13)λ,理论误差达到高精度平面面形检测要求。     

Conformally flat spaces and gravitation

This article considers the theory of gravity which is defined by R ² as the free Lagrangian. The resulting equations are conformally invariant, and their equivalence to Einstein's equation is demonstrated (provided the stress tensor is traceless). The possibility of adapting this theory to massive point particles on a conformally flat background is discussed.     

扫描平场全息凹面光栅

从全息凹面光栅像差理论出发,考虑到扫描平场光谱仪的结构特点,推广全息凹面光栅优化设计的基本方程使之适用于扫描平场全息凹面光栅(SFHCG),且用在光栅扫描角范围内和在谱面上取点求和来代替复杂的积分运算,简化设计程序。给出一消像散SFHCG的设计实例和用这块光栅所做的实验结果。     

Adsorption and co-adsorption of CH<Subscript>3</Subscript> and H on flat and defective nickel (111) surfaces

We use a periodic density functional theory (DFT) code to study the adsorption of CH₃ and H, as well as their co-adsorption on a Ni(111) surface with and without Ni ad-atom, at a surface coverage of 0.25 monolayer (ML). We systematically investigate the site preference for CH₃ and H. Then we combine CH₃ and H in many co-adsorbed configurations on both surfaces. Methyl and hydrogen adsorption on a flat Ni(111) surface favours the hollow site over the top site. The presence of a Ni ad-atom stabilizes the adsorption of CH₃ better than a flat surface, while hydrogen is more stable on a flat Ni(111) surface. When H and CH₃ are co-adsorbed at nearest Ni neighbours on the (111) surface, their interaction is always repulsive. However, the dissociative adsorption of CH₄ is stabilised when the fragments are infinitely separated. For the co-adsorbed fragments CH₃ and H, in the presence of an ad-atom, the repulsive interaction is lowered, so that the dissociative form of CH₄ is locally stable.     

Self-coupled scalar gravitation

The requirement in scalar theories of gravitation that the source of the field includes the trace of its own stress tensor is investigated in two models: (1) The geometrical Nordstr0m theory, which is the conformally flat metric analog of Einstein's theory. (2) The ostensibly non-geometrical flat space system of Freund and Nambu. Both are derived in closed form as cubic self-interacting systems and shown to be equivalent.Supported in part by U.S.A.F., O.A.R. under O.S.R. grant 70-1864.Supported by the National Research Council of Canada under grant 694.     

Conformally invariant differential operators on Minkowski space and their curved analogues

This article describes the construction of a natural family of conformally invariant differential operators on a four-dimensional (pseudo-)Riemannian manifold. Included in this family are the usual massless field equations for arbitrary helicity but there are many more besides. The article begins by classifying the invariant operators on flat space. This is a fairly straightforward task in representation theory best solved through the theory of Verma modules. The method generates conformally invariant operators in the curved case by means of Penrose's local twistor transport.S.E.R.C. Advanced Fellow and Flinders University Visiting Research Fellow     

Two-dimensional topological gravity and intersection theory on the moduli space of holomorphic bundles

We define a two-dimensional topological Yang-Mills theory for an arbitrary compact simple Lie group. This theory is defined in terms of intersection theory on the moduli space of flat connections on a two-dimensional surface and corresponds physically to a two-dimensional reduction and truncation of four-dimensional topological Yang-Mills theory. Two-dimensional topological Yang-Mills theory defines a topological matter system and may be naturally coupled to two-dimensional topological gravity. This topological Yang-Mills theory is also closely related to Chern-Simons gauge theory in 2 + 1 dimensions. We also discuss a relation between SL (2, ) Chern-Simons theory and two-dimensional topological gravity.     

Tailoring the structure of water at a metal surface: a structural analysis of the water bilayer formed on an alloy template

Recent studies show that structures based on the traditional "icelike" water bilayer are not stable on flat transition metal surfaces and, instead, more complex wetting layers are formed. Here we show that an ordered bilayer can be formed on a SnPt(111) alloy template and determine the structure of the water layer by low energy electron diffraction. Close agreement is found between experiment and the structure calculated by density functional theory. Corrugation of the alloy surface allows only alternate water molecules to chemisorb, stabilizing the H-down water bilayer by reducing the metal-hydrogen repulsion compared to a flat surface.     

Relativistic action-at-a-distance interactions: Lagrangian and Hamiltonian to terms of second order

Relativistic systems of particles interacting pairwise at a distance (interactions not mediated by fields) in flat spacetime are studied. It is assumed that the interactions propagate at the speed of light in vacuum and that all masses are scalars under Poincaré transformations. The action functional of the theory depends on multiple times (the proper times of the particles). In the static limit, the theory has three components: a linearly rising potential, a Coulomb-like interaction and a dynamical component to the Poincaré invariant mass. In this Letter we obtain explicitly, to terms of second order, the Lagrangian and the Hamiltonian with all the dynamical variables depending on a single time. Approximate solutions of the relativistic two-body problem are presented.     

Fluctuation electromagnetic interaction of moving particles with a cylindrical surface and a channel

The most general (nonrelativistic) analytical formulas are deduced in the framework of the fluctuation electromagnetic theory for the dynamic conservative and dissipative forces experienced by a neutral atom moving parallel to the generatrix of a cylindrical surface. As in the case of a flat surface, a finite friction force proportional to the velocity exists at T=0.     

Special relativistic Newtonian gravity

Newtonian gravity is modified minimally to obtain a Lorentz covariant theory of gravity in a background flat space. Gravity is assumed to appear as a potential. Constraint Hamiltonian dynamics is used to determine particle trajectories in a manifestly covariant fashion. The resulting theory is significantly different from the general theory of relativity. However, all known experimental results (precession of planetary orbits, bending of the path of light near the sun, and gravitational spectral shift) are still explained by this theory.