A new doubling algorithm – Alternating-Directional Doubling Algorithm (ADDA) – is developed for computing the unique minimal nonnegative solution of an M -Matrix Algebraic Riccati Equation (MARE). It is argued by both theoretical analysis and numerical experiments that ADDA is always faster than two existing doubling algorithms – SDA of Guo, Lin, and Xu (Numer. Math., 103 (2006), pp. 393–412) a...

We study tautological vector bundles over the Hilbert scheme of points on surfaces. For each K-trivial surface, we write down a simple criterion ensuring that are big and nef, illustrate it by examples. In K3 case, extend recent constructions results Bini, Boissi\`ere Flamini from 2 3 to an arbitrary number points. Among surfaces, case Enriques surfaces is most involved. Our techniques apply ot...

C. B. Azzoni , M. C. Mozzat i , A. Paleari , M . Bini b , D. Capsoni b , G. Chiodel l i b , and V. Massarot t i b INFM-Department of Physics "A. Volta" of the University, via Bassi 6,1-27100 Pavia a INFM-Department of Materials Science of the University, via Cozzi 53,1-20125 Milano b Department of Physical Chemistry of the University and CSTE-CNR, via Taramelli 16,1-27100 Pavia Reprint requests...