Search results for "Jacob"

Motives of quadric bundles and relative intermediate jacobians of K3-Fano pairs

2015

This thesis consists of two parts. In the first part we study the Chow motive of a quadric bundle of odd relative dimension over a surface. We show that this motive admits a decomposition which involves the Prym motive of the double covering of the discriminant curve.In the second part, we consider Lagrangian fibrations, obtained as relative intermediate Jacobians of families of Fano threefolds containing a fixed K3 surface, and the existence of a symplectic compactification. In a particular case, we study a partial compactification using calculations with the software system Macaulay2.

On the rigidity theorem for elliptic genera

2018

We give a detailed proof of the rigidity theorem for elliptic gen- era. Using the Lefschetz fixed point formula we carefully analyze the relation between the characteristic power series defining the elliptic genera and the equivariant elliptic genera. We show that equivariant elliptic genera converge to Jacobi functions which are holomorphic. This implies the rigidity of elliptic genera. Our approach can be easily modified to give a proof of the rigidity theorem for the elliptic genera of level N.

A-superharmonic functions and supersolutions of degenerate elliptic equations

1988

Planar Mappings of Finite Distortion

2010

We review recent results on planar mappings of finite distortion. This class of mappings contains all analytic functions and quasiconformal mappings.

Radical Rings with Soluble Adjoint Groups

2002

Abstract An associative ring R , not necessarily with an identity, is called radical if it coincides with its Jacobson radical, which means that the set of all elements of R forms a group denoted by R ∘ under the circle operation r  ∘  s  =  r  +  s  +  rs on R . It is proved that every radical ring R whose adjoint group R ∘ is soluble must be Lie-soluble. Moreover, if the commutator factor group of R ∘ has finite torsion-free rank, then R is locally nilpotent.

Suicidi

2020

I suicidi, eventi drammatici come pochi altri, hanno da sempre costituito una sfida per l’immaginazione sociologica. Se Emile Durkheim aveva dimostrato le capacità esplicative della sociologia, le sociologie costruzioniste – e, in particolare, interazionismo simbolico, etnometodologia, fenomenologia – hanno operato la resa dei conti con gli approcci positivisti. I saggi che qui presentiamo offrono una summa di grande interesse dei modi originali con cui le sociologie costruzioniste hanno re-immaginato lo studio dei suicidi andando oltre la rigidità dello schema “cause e cure” degli approcci positivisti ed arricchendo di sfumature la nostra comprensione del fenomeno. Di fronte a un panorama …

The PCHIP subdivision scheme

2016

In this paper we propose and analyze a nonlinear subdivision scheme based on the monotononicity-preserving third order Hermite-type interpolatory technique implemented in the PCHIP package in Matlab. We prove the convergence and the stability of the PCHIP nonlinear subdivision process by employing a novel technique based on the study of the generalized Jacobian of the first difference scheme. MTM2011-22741

Applications to Algebraic Cycles: Nori's Theorem

2017

Deligne cohomology is a tool that makes it possible to unify the study of cycles through an object that classifies extensions of ( p , p )-cycles by points in the p -th intermediate Jacobian (which is the target of the Abel–Jacobi map on cycles of codimension p ). This is treated in Section 10.1 with applications to normal functions. Before giving the proof of Nori's theorem in Section 10.6, we need some results from mixed Hodge theory. These are proven in Section 10.2 where we also state different variants of the theorem. Sections 10.3 and 10.4 treat a localto- global principle and an extension of the method of Jacobian representations of cohomology which are both essential for the proof. …

Chemical composition of the essential oil of Jacobaea maritima (L.) PelserMeijden and Jacobaea maritima subsp. bicolor (Willd.) B. Nord.Greuter (Aste…

2015

In this study, the chemical compositions of the essential oils from aerial parts (JmA) and radices (JmR) of Jacobaea maritima (L.) Pelser & Meijden, collected in Croatia, and of Jacobaea maritima subsp. bicolor (Willd.) B. Nord. & Greuter, collected in Sicily, were evaluated by using gas chromatography and gas chromatography–mass spectrometry. The main components of the essential oil from J. maritima, both in JmA and JmR, were pentacosane (15.7%), heptacosane (13.1%) and nonacosane (8.1%) whereas the essential oil from J. maritima subsp. bicolor was characterised by the presence of hexadecanoic acid (14.6%), caryophyllene oxide (9.3%) and hexahydrofarnesylacetone (6.5%). The comparison of t…

Observations on population dynamics of leafhoppers in Western Sicily vineyards

2013

From 2007 to 2009 field observations were carried out in two vineyards (organically and conventionally managed) in Menfi (Agrigento province, Sicily). Population dynamics of two leafhoppers, Jacobiasca lybica (cotton leafhopper) and Zygina rhamni were followed by chromotropic traps and leaf observation in field. Both species were constantly present in vineyards. Z. rhamni did not register statistical differences between the two fields, while J. lybica was mostly present in the conventionally managed field. In this last vineyard for two consecutive years (2007 and 2008) J. lybica population exceeded the intervention threshold of 0.5 leafhopper/leaf. On the other hand, in the organically mana…