Abstract An NP-hardness proof for non-local Multicomponent Tree Adjoining Grammar (MCTAG) by Rambow and Satta (1992), based on Dahlhaus and Warmuth (1986), is extended to some linguistically relevant restrictions of that formalism. It is found that there are NP-hard grammars among non-local MCTAGs even if any or all of the following restrictions are imposed: (i) lexicalization: every tree in th...

We show that Ambro–Kawamata’s non-vanishing conjecture holds true for a quasi-smooth WCI X which is Fano or Calabi-Yau, i.e. we prove that, if H is an ample Cartier divisor on X , then |H | is not empty. If X is smooth, we further show that the general element of |H | is smooth. We then verify Ambro–Kawamata’s conjecture for any quasi-smooth weighted hypersurface. We also verify Fujita’s freene...

In previous work of the authors and their collaborators (see, e.g., Progress in Math. 114, Birkhäuser (1993)) it was shown how the equivalence of several constructions of residue currents associated to complete intersection families of (germs of) holomorphic functions in C could be profitably used to solve algebraic problems like effective versions of the Nullstellensatz. In this work, the auth...

A new kind of dynamics for simulations based upon quantum-classical hybrid is discussed. The model is represented by a modified Madelung equation in which the quantum potential is replaced by different, specially chosen potentials. As a result, the dynamics attains both quantum and classical properties: it preserves superposition and entanglement of random solutions, while allowing one to measu...

We study obstructions to existence of non-commutative crepant resolutions, in the sense of Van den Bergh, over local complete intersections.

We consider the non-preemptive task scheduling problem with release times and deadlines on a single machine parameterized by the set of task lengths the tasks can have. The identical task lengths case is known to be solvable in polynomial time. We prove that the problem with two task lengths is NP-complete, except for the case in which the short jobs have unit task length, which was already kno...

In this paper, we study gradient Ricci expanding solitons (X, g) satisfying Rc = cg +Df, where Rc is the Ricci curvature, c < 0 is a constant, and Df is the Hessian of the potential function f on X . We show that for a gradient expanding soliton (X, g) with non-negative Ricci curvature, the scalar curvature R has at least one maximum point on X , which is the only minimum point of the potential...

By a hyperbolization of a locally compact non-complete metric space (X, d) we mean equipping X with a Gromov hyperbolic metric dh so that the boundary at infinity ∂∞X of (X, dh) can be identified with the metric boundary ∂X of (X, d) via a quasisymmetric map. The aim of this note is to show that the Gromov hyperbolic metric dh, recently introduced by the author, hyperbolizes the space X. In add...

We consider the simplest network of coupled non-identical phase oscillators capable of displaying a "chimera" state (namely, two subnetworks with strong coupling within the subnetworks and weaker coupling between them) and systematically investigate the effects of gradually removing connections within the network, in a random but systematically specified way. We average over ensembles of networ...

Database transformations provide a unifying framework for database queries and updates. Recently, it was shown that non-deterministic database transformations can be captured exactly by a variant of ASMs, the so-called Database Abstract State Machines (DB-ASMs). In this article we present a logic for DB-ASMs, extending the logic of Nanchen and Stärk for ASMs. In particular, we develop a rigorou...