Now showing items 1-20 of 39

    • A Lê-Greuel type formula for the image Milnor number 

      Nuño-Ballesteros J.J.; Pallarés Torres I. (Hokkaido Mathematical Journal, 2019-02)
      Let $f\colon (\mathbb{C}^n,0)\to (\mathbb{C}^{n+1},0)$ be a corank 1 finitely determined map germ. For a generic linear form $p\colon (\mathbb{C}^{n+1},0)\to(\mathbb{C},0)$ we denote by $g\colon (\mathbb{C}^{n-1},0)\to ...
    • Examples of varieties with index one on C1 fields 

      Dan A.; Kaur I. (Journal of Number Theory, 2019-04-16)
      Let K be the fraction field of a Henselian discrete valuation ring with algebraically closed residue field k. In this article we give a sufficient criterion for a projective variety over such a field to have index 1.
    • Perverse sheaves on semi-abelian varieties -- a survey of properties and applications 

      Liu Y.; Maxim L.; Wang B. (European Journal of Mathematics, 2019-05)
      We survey recent developments in the study of perverse sheaves on semi-abelian varieties. As concrete applications, we discuss various restrictions on the homotopy type of complex algebraic manifolds (expressed in terms ...
    • On Lipschitz rigidity of complex analytic sets 

      Fernandes A.; Sampaio J. E. (The Journal of Geometric Analysis, 2019-02-26)
      We prove that any complex analytic set in $\mathbb{C}^n$ which is Lipschitz normally embedded at infinity and has tangent cone at infinity that is a linear subspace of $\mathbb{C}^n$ must be an affine linear subspace of ...
    • A jacobian module for disentanglements and applications to Mond's conjecture 

      Fernández de Bobadilla J.; Nuño Ballesteros J. J.; Peñafort Sanchis G. (Revista Matemática Complutense, 2019)
      Let $f:(\mathbb C^n,S)\to (\mathbb C^{n+1},0)$ be a germ whose image is given by $g=0$. We define an $\mathcal O_{n+1}$-module $M(g)$ with the property that $\mathscr A_e$-$\operatorname{codim}(f)\le \dim_\mathbb C M(g)$, ...
    • On Zariski’s multiplicity problem at infinity 

      Sampaio J. E. (Proceedings of the American Mathematical Society, 2018-08-14)
      We address a metric version of Zariski's multiplicity conjecture at infinity that says that two complex algebraic affine sets which are bi-Lipschitz homeomorphic at infinity must have the same degree. More specifically, ...
    • Singularities in Geometry and Topology 

      Romano A. (2018-06-18)
      This thesis consists of two different topics that are not related. The thesis has two different and independent parts that can be read in any order. The purpose of this work is to study two topics in singularity theory: ...
    • Right unimodal and bimodal singularities in positive characteristic 

      Nguyen H.D. (International Mathematics Research Notices, 2017-08-07)
      The problem of classification of real and complex singularities was initiated by Arnol'd in the sixties who classified simple, unimodal and bimodal singularities w.r.t. right equivalence. The classification of simple ...
    • Multiplicity and degree as bi‐Lipschitz invariants for complex sets 

      Fernandes A.; Fernández de Bobadilla J.; Sampaio J. E. (Journal of Topology, 2018-08-29)
      We study invariance of multiplicity of complex analytic germs and degree of complex affine sets under outer bi-Lipschitz transformations (outer bi-Lipschitz homeomorphims of germs in the first case and outer bi-Lipschitz ...
    • On the geometry of strongly flat semigroups and their generalizations 

      László T.; Némethi A. (2018-09-18)
      Our goal is to convince the readers that the theory of complex normal surface singularities can be a powerful tool in the study of numerical semigroups, and, in the same time, a very rich source of interesting affine and ...
    • Surgery formulae for the Seiberg-Witten invariant of plumbed 3-manifolds 

      László T.; Nagy J.; Némethi A. (2017-02)
      Assume that $M(\mathcal{T})$ is a rational homology sphere plumbed 3--manifold associated with a connected negative definite graph $\mathcal{T}$. We consider the combinatorial multivariable Poincar\'e series associated ...
    • Combinatorial duality for Poincaré series, polytopes and invariants of plumbed 3-manifolds 

      László T.; Nagy J.; Némethi A. (2018-06)
      Assume that the link of a complex normal surface singularity is a rational homology sphere. Then its Seiberg-Witten invariant can be computed as the ‘periodic constant’ of the topological multivariable Poincaré series (zeta ...
    • Némethi’s division algorithm for zeta-functions of plumbed 3-manifolds 

      László T.; Szilágyi Zs. (Bulletin of the London Mathematical Society, 2018-08-27)
      A polynomial counterpart of the Seiberg-Witten invariant associated with a negative definite plumbing 3-manifold has been proposed by earlier work of the authors. It is provided by a special decomposition of the zeta-function ...
    • Some classes of homeomorphisms that preserve multiplicity and tangent cones 

      Sampaio J. E. (2018-08-19)
      In this paper it is presented some classes of homeomorphisms that preserve multiplicity and tangent cones of complex analytic sets. Moreover, we present a class of homeomorphisms that has the multiplicity as an invariant ...
    • Semialgebraic CMC surfaces in $\mathbb{R}^3$ with singularities 

      Sampaio J. E. (2018-06-30)
      In this paper we present a classification of a class of semialgebraic CMC surfaces in $\mathbb{R}^3$ that generalizes the recent classification made by Barbosa and do Carmo in 2016 (complete reference is in the paper), we ...
    • Hölder equivalence of complex analytic curve singularities 

      Fernandes A.; Sampaio J. E.; Silva J. P. (Bulletin of the London Mathematical Society, 2018-08-06)
      We prove that if two germs of irreducible complex analytic curves at $0\in\mathbb{C}^2$ have different sequence of characteristic exponents, then there exists $0<\alpha<1$ such that those germs are not $\alpha$-H\"older ...
    • The Nash Problem from a Geometric and Topological Perspective 

      Fernández de Bobadilla J.; Pe Pereira M. (2018-04-17)
      We survey the proof of the Nash conjecture for surfaces and show how geometric and topological ideas developed in previous articles by the au- thors influenced it. Later we summarize the main ideas in the higher dimen- ...
    • Monodromies as tête-à-tête graphs 

      Portilla Cuadrado P. (2018-05-08)
    • Mixed tête-à-tête twists as monodromies associated with holomorphic function germs 

      Portilla Cuadrado P.; Sigurdsson B. (2018-04-01)
      Tête-à-tête graphs were introduced by N. A’Campo in 2010 with the goal of modeling the monodromy of isolated plane curves. Mixed tête-à-tête graphs provide a generalization which define mixed tête-à-tête twists, which ...