We develop a new, more functorial construction for the basic theory of limit linear series, which provides a compactification of the Eisenbud-Harris theory, and shows promise for generalization to higher-dimensional varieties and higher-rank vector bundles. We also give a result on lifting linear series from characteristic p to characteristic 0. In an appendix, in order to obtain the necessary dimensional lower bounds on our limit linear series scheme we develop a theory of "linked Grassmannians;" these are schemes parametrizing sub-bundles of a sequence of vector bundles which map into one another under fixed maps of the ambient bundles.
ABSTRACT. We prove that if X, X ′ are closed subschemes of a torus T over a non-Archimedean field K, of complementary codimension and with finite intersection, then the stable tropical intersection along a (possibly positive-dimensional, possibly unbounded) connected component C of Trop(X)∩ Trop(X ′ ) lifts to algebraic intersection points, with multiplicities. This theorem requires potentially passing to a suitable toric variety X(∆) and its associated extended tropicalization N R (∆); the algebraic intersection points lifting the stable tropical intersection will have tropicalization somewhere in the closure of C in N R (∆). The proof involves a result on continuity of intersection numbers in the context of non-Archimedean analytic spaces.
A set of fundamental matrices relating pairs of cameras in some configuration can be represented as edges of a "viewing graph". Whether or not these fundamental matrices are generically sufficient to recover the global camera configuration depends on the structure of this graph. We study characterizations of "solvable" viewing graphs, and present several new results that can be applied to determine which pairs of views may be used to recover all camera parameters. We also discuss strategies for verifying the solvability of a graph computationally.
In the 1990's, Bertram, Feinberg and Mukai examined Brill-Noether loci for vector bundles of rank 2 with fixed canonical determinant, noting that the dimension was always bigger in this case than the naive expectation. We generalize their results to treat a much broader range of fixed-determinant Brill-Noether loci. The main technique is a careful study of symplectic Grassmannians and related concepts.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.