There is considerable interest among computational linguists in lexicalized grammatical frameworks; lexicalized tree adjoining grammar (LTAG) is one widely studied example. In this paper, we investigate how derivations in LTAG can be viewed not as manipulations of trees but as manipulations of tree descriptions. Changing the way the lexicalized formalism is viewed raises questions as to the des...

We consider C/ZN and C/ZN orbifolds of heterotic string theories and ZN orbifolds of AdS3. We study theories with N=2 worldsheet superconformal invariance and construct RG flows. Following Harvey, Kutasov, Martinec and Moore, we compute gcl and show that it decreases monotonically along RG flowsas conjectured by them. For the heterotic string theories, the gauge degrees of freedom do not contri...

We have results from light hadron simulations in quenched QCD at β = 6.0 and 6.2 using non-perturbatively improved Sheikholeslami–Wohlert fermions in an effort to remove all O(a) effects. From looking at hadron masses and splittings and the RG-invariant quark masses (where we have one point at β = 5.7) we suggest this is plausible even with the limited data set. The interpretation of the decay ...

Accurate determinations of the MS b-quark mass mb (mb) from σ (e +e− → hadrons) experimental data currently contain three comparable sources of uncertainty; the experimental uncertainty from moments of this cross-section, the uncertainty associated with αs (Mz), and the theoretical uncertainty associated with the renormalization scale. Through resummation of all logarithmic terms explicitly det...

The renormalization group (RG) method is one of the singular perturbation methods which is used in search for asymptotic behavior of solutions of differential equations. In this article, time-independent vector fields and time (almost) periodic vector fields are considered. Theorems on error estimates for approximate solutions, existence of approximate invariant manifolds and their stability, i...

We consider C/ZN and C/ZN orbifolds of heterotic string theories and ZN orbifolds of AdS3. We study theories with N=2 worldsheet superconformal invariance and construct RG flows. Following Harvey, Kutasov, Martinec and Moore, we compute gcl and show that it decreases monotonically along RG flowsas conjectured by them. For the heterotic string theories, the gauge degrees of freedom do not contri...

We discuss the fate of certain tachyonic closed string theories from two perspectives. In both cases our approach involves studying directly configurations with finite negative treelevel cosmological constant. Closed string analogues of orientifolds, which carry negative tension, are argued to represent the minima of the tachyon potential in some cases. In other cases, we make use of the fact, ...

We study five-dimensional gravity models with non-vanishing background scalar fields which are dual to non-conformal boundary field theories. We develop a procedure to decouple the graviton fluctuations from the scalar ones and apply it to the simplest case of one scalar field. The quadratic action for the decoupled scalar fluctuations has a very simple form and can be used to compute two-point...

The Border Gateway Protocol (BGP) is the protocol used to distribute Internet routes between different organizations. BGP routing policies are very important because they enable organizations to enforce their business relationships by controlling route redistribution and route selection. In this paper, we investigate the semantic of BGP policies. We aim to determine whether two policies are equ...

We discuss the role of the dilaton tadpole in the holographic description of non-supersymmetric gauge theories that are conformal in the planar limit. On the string theory side, the presence of the dilaton tadpole modifies the AdS background inducing a logarithmic running for the radius and the dilaton. Using the holographic prescription we compute the Wilson loop on the gravity side and find a...