We review the basics of the dynamics of closed strings moving along the infinite discretized line ZZ. The string excitations are described by a field φx(τ) where x ∈ ZZ is the position of the string in the embedding space and τ is a semi-infinite “euclidean time” parameter related to the longitudinal mode of the string. Interactions due to splitting and joining of closed strings are taken into ...

2014 The spins in a ferromagnet define a vector field. Their simplest line singularities are therefore disclinations of unit strength, and their point singularities are of the types analysed by Poincaré. A nematic liquid crystal is normally unpolarised. As a result, a vector placed along the nematic axis at a point may be carried continuously through « good » liquid crystal and return inverted....

Let (M, g) be a compact Kähler-Einstein manifold with c1 > 0. Denote by K → M the canonical line-bundle, with total space X, and X0 the singular space obtained by blowing down X along its zero section. We employ a construction by Page and Pope and discuss an interesting multi-parameter family of Poincaré–Einstein metrics on X. One 1-parameter subfamily {gt}t>0 has the property that as t ↘ 0, gt...

The recent discoveries of X-ray lines in the afterglows of gamma-ray bursts (GRBs) provide significant clues to the nature of GRB progenitors and central environments. However, the iron line interpretation by fluorescence or recombination mechanism involves the request for the large amount of iron material. We argue that the very strong iron line could be attributed to an alternative mechanism:...

Let (M, g) be a compact Kähler-Einstein manifold with c1 > 0. Denote by K → M the canonical line-bundle, with total space X, and X0 the singular space obtained by blowing down X along its zero section. We employ a construction by Page and Pope and discuss an interesting multi-parameter family of Poincaré–Einstein metrics on X. One 1-parameter subfamily {gt}t>0 has the property that as t ց 0, gt...

Let X be a smooth projective variety defined over field k of characteristic 0 and let L nef line bundle k. We prove that if x∈X is k-rational point then the Seshadri constant ε(X,L,x) k‾ same as show, by constructing families examples, there are varieties whose global ε(X) zero. also result on existence curve with natural (and necessary) hypothesis.

In this paper, full-film lubrication between the rigid smooth and dimpled surfaces was addressed. A theoretical model is developed to study effect of a dimple on friction where surface rotating while at rest. To simplify problem, magnified cell investigated along with some assumptions. Because dimples deploy periodically x y directions, lubricant pressure also deploys periodically. can be for o...

over certain thin strips L in the plane are measured through x-ray transmission along L. How can we recover f(x,y)? Previous reconstruction algorithms fall into two broad categories: (a) Algorithms based on a formula, typically the Fourier inversion formula.lvE (b) Search algorithms, typically based on iterative relaxation.2,4 We have chosen a particular f(x,y), Fig. 1, felt to be a reasonable ...