Elementary nets (carpets) over a discrete valuation ring

Fano Fibrations over a Discrete Valuation Ring

Using the Log minimal model program we construct nice models of del Pezzo fibrations which are relevant to the inductive study of del Pezzo fibrations. To investigate birational maps of Fano fibrations, we study elements in anticanonical linear systems of Fano varieties, which have the “worst” singularities. We also investigate certain special points on smooth hypersurfaces of degree n ≥ 3 in P...

Lifting Lie Algebras over the Residue Field of a Discrete Valuation Ring

Let R be a discrete valuation ring with maximal ideal πR and residue field k. We study obstructions to lifting a Lie algebra L over R/πR to one over R/πR. If L̄ is the Lie algebra over k obtained from reducing L then we show there exists a well-defined class in H(L̄, ad) which vanishes if and only if L lifts. Furthermore, if L lifts, the lifts are shown to be in one to one correspondence with H(L̄...

Witt group of Hermitian forms over a noncommutative discrete valuation ring

We investigate Hermitian forms on finitely generated torsion modules over a noncommutative discrete valuation ring. We also give some results for lattices, which still are satisfied even if the base ring is not commutative. Moreover, for a noncommutative discrete-valued division algebra D with valuation ring R and residual division algebra D̄, we prove that W(D̄) ∼=WT(R), where WT(R) denotes the ...

Filtered Modules over Discrete Valuation Domains

We consider a uni ed setting for studying local valuated groups and coset-valuated groups, emphasizing the associated ltrations rather than the values of elements. Stable exact sequences, projectives and injectives are identi ed in the encompassing category, and in the category corresponding to coset-valuated groups.

Bernstein's Theorem over Fields with Discrete Valuation