Concept
Birational geometry
Related publications (23)
Birational characterization of abelian varieties and ordinary abelian varieties in characteristic p>0
Let k be an algebraically closed field of characteristic p > 0. We give a birational characterization of ordinary abelian varieties over k: a smooth projective variety X is birational to an ordinary abelian variety if and only if kappa(S)(X) = 0 and b(1)(X ...
DUKE UNIV PRESS2019Applications of one-point extensions to compute the A∞-(co)module structure of several Ext (resp., Tor) groups
Let A be a nonnegatively graded connected algebra over a noncommutative separable k-algebra K, and let M be a bounded below graded right A-module. If we denote by T the -coalgebra , we know that there exists an -comodule structure on over T. The structure ...
2019Using torsion theory to compute the algebraic structure of Hochschild (co)homology
The aim of this article is to provide explicit formulas for the cup product on the Hochschild cohomology of any nonnegatively graded connected algebra and for the cap products on the Hochschild homology of with coefficients in any graded bimodule at the le ...
2018Frobenius techniques in birational geometry
This is a survey for the 2015 AMS Summer Institute on Algebraic Geometry about the Frobenius type techniques recently used extensively in positive characteristic algebraic geometry. We first explain the basic ideas through simple versions of the fundamenta ...
2017Density of rational points on del Pezzo surfaces of degree one
We state conditions under which the set S(k) of k-rational points on a del Pezzo surface S of degree 1 over an infinite field k of characteristic not equal to 2 or 3 is Zariski dense. For example, it suffices to require that the elliptic fibration S -> P-1 ...
Academic Press Inc Elsevier Science2014Arithmetic of del Pezzo surfaces of degree 4 and vertical Brauer groups
We show that Brauer classes of a locally solvable degree 4 del Pezzo surface X are vertical for some projection away from a plane g : X -> P-1, i.e., that every Brauer class is obtained by pullback from an element of Br k(P-1). As a consequence, we prove t ...
Academic Press Inc Elsevier Science2014Design and Fabrication of Robot-Manufactured Joints for a Curved-Folded Thin-Shell Structure Made from CLT
Yves Weinand, Christopher Werner Matthias Robeller, Seyed Sina Nabaei
The prototype presented in this chapter utilizes the technique of curved folding for the design of a thin-shell structure built from curved cross-laminated timber panels (CLT). The curved-folded geometry allows for a span of 13.5 m, at a shell thickness of ...
Springer International Publishing2014Geometry-Induced Rigidity in Nonspherical Pressurized Elastic Shells
Pedro Miguel Nunes Pereira de Almeida Reis
We present results from an experimental investigation of the indentation of nonspherical pressurized elastic shells with a positive Gauss curvature. A predictive framework is proposed that rationalizes the dependence of the local rigidity of an indented sh ...
American Physical Society2012On the Hilbert Transform of Wavelets
Michaël Unser, Kunal Narayan Chaudhury
A wavelet is a localized function having a prescribed number of vanishing moments. In this correspondence, we provide precise arguments as to why the Hilbert transform of a wavelet is again a wavelet. In particular, we provide sharp estimates of the locali ...
IEEE2011Electrical breakdown at low pressure for planar microelectromechanical systems with 10- to 500-micron gaps
An experimental study of the dc breakdown voltage for planar MEMS interdigitated aluminum electrodes with gaps ranging from 10 to 500 micron is presented. Unlike most research on the breakdown in MEMS electrodes that was performed at atmospheric pressure, ...
2009