Semigroup of a quasiordinary singularity
We prove that any finite set of n-dimensional isolated algebraic singularities can be afforded on a simply connected projective variety.
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...
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...
This paper is part of the author's thesis, recently presented, where the following problem is treated: Characterizing the tangent cone and the equimultiple locus of a Puiseux surface (that is, an algebroid embedded surface admitting an equation whose roots are Puiseux power series) , using a set of exponents appearing in a root of an equation. The aim is knowing to which extent the well known results for the quasi-ordinary case can be extended to this much wider family.
Let be a reduced, equidimensional germ of an analytic singularity with reduced tangent cone . We prove that the absence of exceptional cones is a necessary and sufficient condition for the smooth part of the specialization to the tangent cone to satisfy Whitney’s conditions along the parameter axis . This result is a first step in generalizing to higher dimensions Lê and Teissier’s result for hypersurfaces of which establishes the Whitney equisingularity of and its tangent cone under...