Simply-connected algebraic surfaces of positive index.
Simultaneous resolution of rational singularities
Simultaneous Resolution of Threefold Double Points.
Singular sufaces and the rigidity of IP3.
Singularités de Klein - I
Singularités de Klein - II
Singularités imposables en position générale à une hypersurface projective
Singularities II: Automorphisms of Forms.
Singularities of Algebraic Surfaces with C* Action.
Singularities of the moduli spaces of certain abelian surfaces
Singularities of theta divisors and the geometry of
We study the codimension two locus in consisting of principally polarized abelian varieties whose theta divisor has a singularity that is not an ordinary double point. We compute the class for every . For , this turns out to be the locus of Jacobians with a vanishing theta-null. For , via the Prym map we show that has two components, both unirational, which we describe completely. We then determine the slope of the effective cone of and show that the component of the Andreotti-Mayer...
Singularities on complete algebraic varieties
We prove that any finite set of n-dimensional isolated algebraic singularities can be afforded on a simply connected projective variety.
Singularity of the moduli space of stable bundles on surfaces
Small contractions of four dimensional algebraic manifolds.
Small Deformation of Normal Singularities (Erratum).
Small Deformations of Normal Singularities.
Smallness problem for quantum affine algebras and quiver varieties
The geometric small property (Borho-MacPherson [2]) of projective morphisms implies a description of their singularities in terms of intersection homology. In this paper we solve the smallness problem raised by Nakajima [37, 35] for certain resolutions of quiver varieties [37] (analogs of the Springer resolution): for Kirillov-Reshetikhin modules of simply-laced quantum affine algebras, we characterize explicitly the Drinfeld polynomials corresponding to the small resolutions. We use an elimination...
Smooth contractible hypersurfaces in Cn and exotic algebraic structures on C3.
Smooth curves on a cone which pass through its vertex.
Smooth double subvarieties on singular varieties, III
Let k be an algebraically closed field, char k = 0. Let C be an irreducible nonsingular curve such that rC = S ∩ F, r ∈ ℕ, where S and F are two surfaces and all the singularities of F are of the form , s ∈ ℕ. We prove that C can never pass through such kind of singularities of a surface, unless r = 3a, a ∈ ℕ. We study multiplicity-r structures on varieties r ∈ ℕ. Let Z be a reduced irreducible nonsingular (n-1)-dimensional variety such that rZ = X ∩ F, where X is a normal n-fold, F is a (N-1)-fold...