scholarly journals A family of vector bundles on P 3 of homological dimension 2 and χ (EndE) = 1

2020 ◽  
Vol 47 (8) ◽  
Author(s):  
Sérgio Mendes ◽  
Rosa M. Miró-Roig ◽  
Helena Soares
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sérgio Mendes ◽  
Rosa María Miró-Roig ◽  
Helena Soares

Abstract We find the complete integer solutions of the equation X 2 + Y 2 + Z 2 - 4 ⁢ X ⁢ Y - 4 ⁢ Y ⁢ Z + 10 ⁢ X ⁢ Z = 1 X^{2}+Y^{2}+Z^{2}-4XY-4YZ+10XZ=1 . As an application, we prove that, for each solution ( a , b , c ) (a,b,c) such that a > 0 a>0 , b - 2 ⁢ a > 0 b-2a>0 and ( b - 2 ⁢ a ) 2 ≥ 4 ⁢ a (b-2a)^{2}\geq 4a , there is a vector bundle 𝐸 on P 3 \mathbb{P}^{3} defined by a minimal linear resolution 0 → O P 3 ⁢ ( - 2 ) a → O P 3 ⁢ ( - 1 ) b → O P 3 c → E → 0 0\to\mathcal{O}_{\mathbb{P}^{3}}(-2)^{a}\to\mathcal{O}_{\mathbb{P}^{3}}(-1)^{b}\to\mathcal{O}_{\mathbb{P}^{3}}^{c}\to E\to 0 . In particular, 𝐸 satisfies χ ⁢ ( End ⁡ E ) = 1 \chi(\operatorname{End}E)=1 .


1967 ◽  
Vol 63 (3) ◽  
pp. 601-612 ◽  
Author(s):  
K. H. Mayer ◽  
R. L. E. Schwarzenberger

Let X be a compact differentiable manifold of dimension 2m. A differentiable map from X to euclidean (2m + t)-space is an immersion if its Jacobian has rank 2m at each point of X; it is an embedding if it is also one–one. The existence of such an embedding or immersion implies that the characteristic classes of X satisfy certain integrality conditions; these can be used to obtain lower bounds for the integer t. In a similar way many other geometric properties of X can be deduced from a single integrality theorem involving characteristic classes of various vector bundles over X (see for instance (5)).


2015 ◽  
Vol 14 (08) ◽  
pp. 1550121
Author(s):  
Jason Lo

Given a noetherian abelian k-category [Formula: see text] of finite homological dimension, with a tilting object T of projective dimension 2, the abelian category [Formula: see text] and the abelian category of modules over End (T) op are related by a sequence of two tilts; we give an explicit description of the torsion pairs involved. We then use our techniques to obtain a simplified proof of a theorem of Jensen–Madsen–Su, that [Formula: see text] has a three-step filtration by extension-closed subcategories. Finally, we generalize Jensen–Madsen–Su's filtration to the case where T has any finite projective dimension.


2017 ◽  
Vol 29 (3) ◽  
Author(s):  
Rosa María Miró-Roig ◽  
Helena Soares

AbstractWe characterize exceptional vector bundles on


2008 ◽  
Vol 126 (2) ◽  
pp. 143-166 ◽  
Author(s):  
Koichi Kurihara ◽  
Kōta Yoshioka

2011 ◽  
Vol 57 (2) ◽  
pp. 409-416
Author(s):  
Mihai Anastasiei

Banach Lie AlgebroidsFirst, we extend the notion of second order differential equations (SODE) on a smooth manifold to anchored Banach vector bundles. Then we define the Banach Lie algebroids as Lie algebroids structures modeled on anchored Banach vector bundles and prove that they form a category.


Author(s):  
Lorenzo De Biase ◽  
Enrico Fatighenti ◽  
Fabio Tanturri

AbstractWe rework the Mori–Mukai classification of Fano 3-folds, by describing each of the 105 families via biregular models as zero loci of general global sections of homogeneous vector bundles over products of Grassmannians.


Author(s):  
Tom Bachmann ◽  
Kirsten Wickelgren

Abstract We equate various Euler classes of algebraic vector bundles, including those of [12] and one suggested by M. J. Hopkins, A. Raksit, and J.-P. Serre. We establish integrality results for this Euler class and give formulas for local indices at isolated zeros, both in terms of the six-functors formalism of coherent sheaves and as an explicit recipe in the commutative algebra of Scheja and Storch. As an application, we compute the Euler classes enriched in bilinear forms associated to arithmetic counts of d-planes on complete intersections in $\mathbb P^n$ in terms of topological Euler numbers over $\mathbb {R}$ and $\mathbb {C}$ .


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