We give a Hodge-theoretic parametrization of certain real Lie group orbits in the compact dual of a Mumford-Tate domain, and characterize the orbits which contain a naive limit Hodge filtration. A series of examples are worked out for the groups , , and .
Let be a field and be the Grassmannian of -dimensional linear subspaces of . A map is called nesting if for every . Glover, Homer and Stong showed that there are no continuous nesting maps except for a few obvious ones. We prove a similar result for algebraic nesting maps , where is an algebraically closed field of arbitrary characteristic. For this yields a description of the algebraic sub-bundles of the tangent bundle to the projective space .
Using non-Archimedian integration over spaces of arcs of algebraic varieties, we define stringy Euler numbers associated with arbitrary Kawamata log-terminal pairs. There is a natural Kawamata log-terminal pair corresponding to an algebraic variety having a regular action of a finite group . In this situation we show that the stringy Euler number of this pair coincides with the physicists’ orbifold Euler number defined by the Dixon-Harvey-Vafa-Witten formula. As an application, we prove a conjecture...
Inspired by Manin’s approach towards a geometric interpretation of Arakelov theory at infinity, we interpret in this paper non-Archimedean local intersection numbers of linear cycles in with the combinatorial geometry of the Bruhat-Tits building associated to .
Recall that a closed subscheme X ⊂ P is non-obstructed if the corresponding point x of the Hilbert scheme Hilbp(t)n is non-singular. A geometric characterization of non-obstructedness is not known even for smooth space curves. The goal of this work is to prove that subcanonical k-Buchsbaum, k ≤ 2, space curves are non-obstructed. As a main tool we use Serre's correspondence between subcanonical curves and vector bundles.
Using the notion of uniruledness we indicate a class of algebraic varieties which have a stronger version of the cancellation property. Moreover, we give an affirmative solution to the stable equivalence problem for non-uniruled hypersurfaces.