Results from DELPHI on the searches for SM and MSSM Neutral Higgs bosons

These final results from DELPHI searches for the Standard Model SM Higgs boson, together with benchmark scans of the Minimal Supersymmetric Standard Model MSSM neutral Higgs bosons, used data taken at centre-of-mass energies between 200 and 209GeV with a total integrated luminosity of 224inv. pb.The data from 192 to 202GeV are reanalysed with improved b-tagging for MSSM final states decaying to four b-quarks. The 95% confidence level lower mass bound on the Standard Model Higgs boson is 114.1GeV. Mass limits are also given on the lightest scalar and pseudo-scalar Higgs bosons of the MSSM.Comment: Invited talk at the XXIII Physics in Collisions Conference (PIC03), Zeuthen, Germany, June 2003, 3 pages, LaTeX, 2 eps figures. PSN FRAP0

Hodge structures for orbifold cohomology

We construct a polarized Hodge structure on the primitive part of Chen and Ruan's orbifold cohomology $H_{orb}^k(X)$ for projective $SL$-orbifolds $X$ satisfying a ``Hard Lefschetz Condition''. Furthermore, the total cohomology $H_{orb}^{*,*}(X)$ forms a mixed Hodge structure that is polarized by every element of the K\"ahler cone of $X$. Using results of Cattani-Kaplan-Schmid this implies the existence of an abstract polarized variation of Hodge structure on the complexified K\"ahler cone of $X$. This construction should be considered as the analogue of the abstract polarized variation of Hodge structure that can be attached to the singular cohomology of a crepant resolution of $X$, in the light of the conjectural correspondence between the (quantum) orbifold cohomology and the (quantum) cohomology of a crepant resolution.Comment: Streamlined exposition. Added examples. Final versio

The Common Agricultural Policy and EU Enlargement: Implications for Agricultural Production in the Central and Eastern European Countries

This paper focuses on the consequences that an extension of the Common Agricultural Policy could have on agricultural production in the Central and Eastern European Countries. It reviews the evidence presented by recent attempts to quantify the potential impacts of accession on production levels in the CEECs. It also takes into account results from previous studies in order to analyse the importance that structural constraints might have on the capacity of the CEECs' agricultural sectors to respond to supply incentives under accession to the EU, and to examine some research questions that are still unanswered in relation to the supply potential of the CEECs. Some conclusions and policy recommendations are drawn at the end.CAP, CEECs, EU enlargement, supply response, structural constraints., Agricultural and Food Policy,

Frobenius Modules and Hodge Asymptotics

We exhibit a direct correspondence between the potential defining the H^{1,1} small quantum module structure on the cohomology of a Calabi-Yau manifold and the asymptotic data of the A-model variation of Hodge structure. This is done in the abstract context of polarized variations of Hodge structure and Frobenius modules.Comment: Updated bibliography. Final version published in Commun. Math. Phy

Asymptotic Hodge theory and quantum products

Assuming suitable convergence properties for the Gromov-Witten potential of a Calabi-Yau manifold $X$ one may construct a polarized variation of Hodge structure over the complexified K\"ahler cone of $X$. In this paper we show that, in the case of fourfolds, there is a correspondence between ``quantum potentials'' and polarized variations of Hodge structures that degenerate to a maximally unipotent boundary point. Under this correspondence, the WDVV equations are seen to be equivalent to the Griffiths' trasversality property of a variation of Hodge structure.Comment: References and comments added. To appear in "Advances in Algebraic Geometry Motivated by Physics", Ed. E. Previatto, Contemporary Mathematic