Results 1 to 10 of about 44 (44)
On Bloch’s map for torsion cycles over non-closed fields
Forum of Mathematics, Sigma, 2023 We generalize Bloch’s map on torsion cycles from algebraically closed fields to arbitrary fields. While Bloch’s map over algebraically closed fields is injective for zero-cycles and for cycles of codimension at most two, we show that the generalization ...
Theodosis Alexandrou, Stefan Schreieder
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Families of curves with Higgs field of arbitrarily large kernel
Bulletin of the London Mathematical Society, Volume 53, Issue 2, Page 493-506, April 2021., 2021 Abstract In this article, we consider the flat bundle U and the kernel K of the Higgs field naturally associated to any (polarized) variation of Hodge structures of weight 1. We study how strict the inclusion U⊆K can be in the geometric case. More precisely, for any smooth projective curve C of genus g⩾2 and any r=0,…,g−1, we construct non‐isotrivial ...
Víctor González‐Alonso, Sara Torelli
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P = W for Lagrangian fibrations and degenerations of hyper-Kähler manifolds
Forum of Mathematics, Sigma, 2021 We identify the perverse filtration of a Lagrangian fibration with the monodromy weight filtration of a maximally unipotent degeneration of compact hyper-Kähler manifolds.
Andrew Harder +3 more
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Extending tamely ramified strict 1-motives into két log 1-motives
Forum of Mathematics, Sigma, 2021 We define két abelian schemes, két 1-motives and két log 1-motives and formulate duality theory for these objects. Then we show that tamely ramified strict 1-motives over a discrete valuation field can be extended uniquely to két log 1-motives over the ...
Heer Zhao
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Nonemptiness of severi varieties on enriques surfaces
Forum of Mathematics, Sigma, 2023 Let $(S,L)$ be a general polarised Enriques surface, with L not numerically 2-divisible. We prove the existence of regular components of all Severi varieties of irreducible nodal curves in the linear system $|L|$ , that is, for any number of
Ciro Ciliberto +3 more
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Variation of stable birational types in positive characteristic [PDF]
Épijournal de Géométrie Algébrique, 2020 Let k be an uncountable algebraically closed field and let Y be a smooth projective k-variety which does not admit a decomposition of the diagonal. We prove that Y is not stably birational to a very general hypersurface of any given degree and dimension.
Stefan Schreieder
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L‐equivalence for degree five elliptic curves, elliptic fibrations and K3 surfaces
Bulletin of the London Mathematical Society, Volume 52, Issue 2, Page 395-409, April 2020., 2020 Abstract We construct non‐trivial L‐equivalence between curves of genus one and degree five, and between elliptic surfaces of multisection index five. These results give the first examples of L‐equivalence for curves (necessarily over non‐algebraically closed fields) and provide a new bit of evidence for the conjectural relationship between L ...
Evgeny Shinder, Ziyu Zhang
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Hyper-K\"ahler Fourfolds Fibered by Elliptic Products [PDF]
Épijournal de Géométrie Algébrique, 2018 Every fibration of a projective hyper-K\"ahler fourfold has fibers which are Abelian surfaces. In case the Abelian surface is a Jacobian of a genus two curve, these have been classified by Markushevich. We study those cases where the Abelian surface is a
Ljudmila Kamenova
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Indicators for adequate diabetes care for the indigenous communities of Ecuador
Health Expectations, 2022 Introduction Diabetes is the second leading cause of death in Ecuador, as 79% of the indigenous population live in rural areas that are difficult to access and have below‐average health resources.
Jimmy Martin‐Delgado +6 more
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COMPACTIFICATIONS OF PEL-TYPE SHIMURA VARIETIES IN RAMIFIED CHARACTERISTICS
Forum of Mathematics, Sigma, 2016 We show that, by taking normalizations over certain auxiliary good reduction integral models, one obtains integral models of toroidal and minimal compactifications of PEL-type Shimura varieties which enjoy many features of the good reduction theory ...
KAI-WEN LAN
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