1,721,162 research outputs found
The equality case in Wu–Yau inequality
No full textIn recent papers Wu-Yau, Tosatti-Yang and Diver-Trapani used some natural differential inequalities on compact Kahler manifolds with quasi negative holomorphic sectional curvature to derive positivity of the canonical bundle. In this note we study the equality case of this inequalities
Torus actions on weakly pseudoconvex spaces
No full textWe show that the univalent local actions of the complexification of a compact connected Lie group K on a weakly pseudoconvex space where K is acting holomorphically have a universal orbit convex weakly pseudoconvex complexification. We also show that if K is a torus, then every holomorphic action of K on a weakly pseudoconvex space extends to a univalent local action of K-C
Fourier coefficients of invariant random fields on homogeneous spaces of compact Lie groups
Full text linkLet T be a random field invariant under the action of a compact group G. We investigate properties of the Fourier coefficients as orthogonality and Gaussianity. In particular we give conditions ensuring that independence of the random Fourier coefficients implies Gaussianity. As a consequence, in general, it is not possible to simulate a non-Gaussian invariant random field through its Fourier expansion using independent coefficients. end{abstract
Framework for Static and Dynamic Friction Identification for Industrial Manipulators
Full text linkEven if friction modeling and compensation is a very important issue for manipulators, quite simple models are often adopted in the industrial world to avoid too heavy solutions from the computational point of view, and because of the difficulty of finding and identifying a model applicable in any motion condition. This article proposes a general framework for friction identification for industrial manipulators with the goal of solving the previous problems through: first, a complete procedure managing all the steps from data acquisition and model identification up to the generation of the code for the implementation into the robot software architecture, second, the possibility of adopting static or dynamic models of different complexity, and third, the development of some modifications in the dynamic friction model so to achieve a reliable friction torque estimation at any velocity and acceleration regime, avoiding unfeasible peaks and overestimation. The results of experimental tests carried out for different manipulators prove the validity and generality of the proposed friction model and identification procedure
Construction of envelopes of holomorphy for some classes of special domains
No full textThe envelope of holomorphy E(OMEGA) of any domain OMEGA in C(n) which is either of circular type or a tube, is constructed in terms of the envelope of a lower dimensional complex space. As consequences, conditions for the univalence of E(OMEGA) are proved
Regularity of Envelopes
No full textLet X be a compact complex manifold of complex dimension n and α be a smooth closed real form on X such that its cohomology class {α}∈H1,1(X,R) is big. In this paper we prove that, given a bounded function f with bounded distributional laplacian in X, the α-psh envelope P(f) is also locally bounded with locally bounded distributional laplacian on the ample locus of {α}
A remark on the codimension of the Green-Griffiths locus of generic projective hypersurfaces of high degree.
Full text linkWe show that for every smooth generic projective hypersurface X in P^{n+1} there exists a proper subvariety Y in X of codimension at least 2 such that for every non-constant holomorphic map f: C--->X one has f(C) is contained in Y, provided that the degree of X is greater than 2^{n^5}. In particular we obtain an affirmative confirmation of the Kobayashi conjecture for threefolds in P^4
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