363,076 research outputs found

    Ulrich bundles on a general blow–up of the plane

    Get PDF
    We prove that on Xn, the plane blown–up at n general points, there are Ulrich line bundles with respect to a line bundle corresponding to curves of degree m passing simply through the n blown–up points, with m less than or equal to 2 times the square root of n 2, and such that the line bundle in question is very ample on Xn. We prove that the number of these Ulrich line bundles tends to infinity with n. We also prove the existence of slope–stable rank–r Ulrich vector bundles on Xn, for n > 2 and any r > 1 and we compute the dimensions of their moduli spaces. These computations imply that Xn is Ulrich wil

    Macht und Gegenmacht im globalen Zeitalter

    Get PDF
    Ressenya de: Bech, Ulrich: Macht und Gegenmacht im globalen Zeitalter. Frankfurt a. M.: Suhrkamp, 2002

    A note on some moduli spaces of Ulrich bundles

    Get PDF
    We prove that the modular component M(r), constructed in the Main Theorem of a former paper of us (published in Adv. Math on 2024), paramatrizing (isomorphism classes of) Ulrich vector bundles of rank r and given Chern classes, on suitable 3-fold scrolls Xe over Hirzebruch surfaces Fe≥0, which arise as tautological embeddings of projectivization of very-ample vector bundles on Fe, is generically smooth and unirational. A stronger result holds for the suitable associated moduli space MFe(r) of vector bundles of rank r and given Chern classes on Fe, Ulrich w.r.t. the very ample polarization c1(Ee)=OFe(3,be), which turns out to be generically smooth, irreducible and unirational

    ACM bundles on cubic surfaces

    Full text link
    In this paper we prove that, for every r≥2r \geq 2, the moduli space MXs(r;c1,c2)M^s_X(r;c_1,c_2) of rank rr stable vector bundles with Chern classes c1=rHc_1=rH and c2=(3r2−r)/2c_2=(3r^2-r)/2 on a nonsingular cubic surface X⊂P3X \subset \mathbb{P}^3 contains a nonempty smooth open subset formed by ACM bundles, i.e. vector bundles with no intermediate cohomology. The bundles we consider for this study are extremal for the number of generators of the corresponding module (these are known as Ulrich bundles), so we also prove the existence of indecomposable Ulrich bundles of arbitrarily high rank on XX.Comment: 25 pages, no figures, references added, Example 3.8 extende

    Key Notes: The Newsletter of the Department of Music

    Get PDF
    Witch Hunt by Ulrich Schltheiss 20th Anniversary Arranged for Saxophones & Percussion Dr. Ben Warsaw Bach Ascending PERCUSSION ALUMNI PERFORMANCE GUEST ARTIST Graham Spice GUEST ARTIST & GEORGIA SOUTHERN UNIVERSITY Double Alumni Eddie Farr GUEST ARTIST Elainie Lollios GUEST LECTURE Matthew Walker, Owner of M & W Custom Trombones GUEST LECTURE Jeff Clark Student Performance
    • …
    corecore