نحن نعالج مبرهنة كولار للحقن من النظرة التحليلية (أو الهندسة التفاضلية). بشكل أكثر دقة، نقدم شرطا خطوط الإنحناء الذي يشير إلى أحكام كولار للحقن الشعبية. يتم تصريح أساسنا لهذا المبرهنة للمخلوق الكاهلي المضغوط، ولكن دليلنا يستخدم مساحة الأشكال الهارمونية على مجموعة زاريسكي مناسبة مع قياس كاهلي مكتمل. لا نحتاج إلى الحيل التغطية، ولا التجزئة، ولا سلسلة اسكترال ليراي.
We treat Kollars injectivity theorem from the analytic (or differential geometric) viewpoint. More precisely, we give a curvature condition which implies Kollar type cohomology injectivity theorems. Our main theorem is formulated for a compact Kahler manifold, but the proof uses the space of harmonic forms on a Zariski open set with a suitable complete Kahler metric. We need neither covering tricks, desingularizations, nor Lerays spectral sequence.
We give a new proof of Kollars conjecture on the pushforward of the dualizing sheaf twisted by a variation of Hodge structure. This conjecture was settled by M. Saito via mixed Hodge modules and has applications in the investigation of Albanese maps. Our technique is the $L^2$-method and we give a concrete construction and proofs of the conjecture. The $L^2$ point of view allows us to generalize Kollars conjecture to the context of non-abelian Hodge theory.
We study linear projections on Pluecker space whose restriction to the Grassmannian is a non-trivial branched cover. When an automorphism of the Grassmannian preserves the fibers, we show that the Grassmannian is necessarily of m-dimensional linear subspaces in a symplectic vector space of dimension 2m, and the linear map is the Lagrangian involution. The Wronski map for a self-adjoint linear differential operator and pole placement map for symmetric linear systems are natural examples.
Transcendental Brauer elements are notoriously difficult to compute. Work of Wittenberg, and later, Ieronymou, gives a method for computing 2-torsion transcendental classes on surfaces that have a genus 1 fibration with rational 2-torsion in the Jacobian fibration. We use ideas from a descent paper of Poonen and Schaefer to remove this assumption on the rational 2-torsion.
Inspired by a theorem of Bhatt-Morrow-Scholze, we develop a stacky approach to crystals and isocrystals on Frobenius-smooth schemes over F_p . This class of schemes goes back to Berthelot-Messing and contains all smooth schemes over perfect fields of characteristic p. To treat isocrystals, we prove some descent theorems for sheaves of Banachian modules, which could be interesting in their own right.
A mixture of an historical article, and of a survey of recent developments, containing also a couple of new results.