English
Related papers

Related papers: Equisingular algebraic approximation of real and c…

200 papers

We define a generalised Euler characteristic for arc-symmetric sets endowed with a group action. It coincides with equivariant homology for compact nonsingular sets, but is different in general. We lay emphasis on the particular case of…

Algebraic Geometry · Mathematics 2007-05-23 Goulwen Fichou

We show that two families of germs of real-analytic subsets in $C^{n}$ are formally equivalent if and only if they are equivalent of any finite order. We further apply the same technique to obtain analogous statements for equivalences of…

Complex Variables · Mathematics 2015-02-16 Dmitri Zaitsev

A question of B. Teissier, inspired by a previous problem of R. Thom, asks whether for any germ of complex analytic hypersurface there exists a germ of complex algebraic hypersurface with the same topological type. Up to now only the case…

Algebraic Geometry · Mathematics 2010-03-01 Javier Fernandez de Bobadilla

Consider real-analytic mapping-germs, (R^n,o)-> (R^m,o). They can be equivalent (by coordinate changes) complex-analytically, but not real-analytically. However, if the transformation of complex-equivalence is identity modulo higher order…

Algebraic Geometry · Mathematics 2026-04-29 Dmitry Kerner

Let $ f_0 $ and $ f_\infty $ be formal power series at the origin and infinity, and $ P_n/Q_n $, with $ \mathrm{deg}(P_n),\mathrm{deg}(Q_n)\leq n $, be a rational function that simultaneously interpolates $ f_0 $ at the origin with order $…

Classical Analysis and ODEs · Mathematics 2022-02-02 M. L. Yattselev

For a germ $(X,0) \subset (\mathbb{C}^n,0)$ of reduced, equidimensional complex analytic singularity its Nash modification can be constructed as an analytic subvariety $ Z \subset \mathbb{C}^n \times G(k,n)$. We give a characterization of…

Algebraic Geometry · Mathematics 2016-08-29 Arturo Giles Flores

We propose a refinement of the notion of blow-Nash equivalence between Nash function germs, which is an analog in the Nash setting of the blow-analytic equivalence defined by T.-C. Kuo. The new definition is more natural and geometric.…

Algebraic Geometry · Mathematics 2007-05-23 Goulwen Fichou

For two variable real analytic function germs we compare the blow-analytic equivalence in the sense of Kuo to the other natural equivalence relations. Our main theorem states that $C^1$ equivalent germs are blow-analytically equivalent.…

Algebraic Geometry · Mathematics 2008-01-18 Satoshi Koike , Adam Parusinski

We consider a countably generated and uniformly closed algebra of bounded functions. We assume that there is a lower semicontinuous, with respect to the supremum norm, quadratic form and that normal contractions operate in a certain sense.…

Functional Analysis · Mathematics 2018-06-29 Michael Hinz , Alexander Teplyaev

A set of valuable universal similarity factorization equalities is established over complex Clifford algebras $\Cn.$ Through them matrix representations of complex Clifford algebras $\Cn$ can directly be derived, and their properties can…

Mathematical Physics · Physics 2007-05-23 Yongge Tian

We prove that every continuous mapping from a separable infinite-dimensional Hilbert space $X$ into $\mathbb{R}^{m}$ can be uniformly approximated by $C^\infty$ smooth mappings {\em with no critical points}. This kind of result can be…

Differential Geometry · Mathematics 2007-05-23 Daniel Azagra , Manuel Cepedello Boiso

We construct the equivariant analytic lattice cohomology associated with the analytic type of a complex normal surface singularity whenever the link is a rational homology sphere. It is the categorification of the equivariant geometric…

Algebraic Geometry · Mathematics 2021-08-31 Tamás Ágoston , András Némethi

We show that for any real-analytic submanifold M in C^N there is a proper real-analytic subvariety V contained in M such that for any point p in M\V, any real-analytic submanifold M' in C^N, and any point p' in M', the germs of the…

Complex Variables · Mathematics 2007-05-23 M. S. Baouendi , Linda Preiss Rothschild , Dmitri Zaitsev

Let X be a separable Banach space which admits a separating polynomial; in particular X a separable Hilbert space. Let $f:X \rightarrow R$ be bounded, Lipschitz, and $C^1$ with uniformly continuous derivative. Then for each {\epsilon}>0,…

Functional Analysis · Mathematics 2010-11-23 D. Azagra , R. Fry , L. Keener

To a Nash function germ, we associate a zeta function similar to the one introduced by J. Denef and F. Loeser. Our zeta function is a formal power series with coefficients in the Grothendieck ring $\mathcal{M}$ of $\mathcal{AS}$-sets up to…

Algebraic Geometry · Mathematics 2017-08-16 Jean-Baptiste Campesato

Let $X$ be an analytic subset of $U\times C^n$ of pure dimension $k$ such that the projection of $X$ onto $U$ is a proper mapping, where $U$ is a Runge domain in $C^k$. We show that $X$ can be approximated by algebraic sets.

Complex Variables · Mathematics 2009-05-13 Marcin Bilski

Let $X$ be a real Banach space with an unconditional basis (e.g., $X=\ell_2$ Hilbert space), $\Omega\subset X$ open, $M\subset\Omega$ a closed split real analytic Banach submanifold of $\Omega$, $E\to M$ a real analytic Banach vector…

Complex Variables · Mathematics 2014-02-26 Imre Patyi , Scott Simon

We define invariants of the blow-Nash equivalence of real analytic function germs, in a similar way that the motivic zeta functions of Denef & Loeser. As a key ingredient, we extend the virtual Betti numbers, which were known for real…

Algebraic Geometry · Mathematics 2007-05-23 Goulwen Fichou

To any Nash germ invariant under right composition with a linear action of a finite group, we associate its equivariant zeta functions, inspired from motivic zeta functions, using the equivariant virtual Poincar\'e series as a motivic…

Algebraic Geometry · Mathematics 2016-05-26 Fabien Priziac

We construct the analytic lattice cohomology associated with the analytic type of any complex normal surface singularity. It is the categorification of the geometric genus of the germ, whenever the link is a rational homology sphere. It is…

Algebraic Geometry · Mathematics 2021-08-30 Tamás Ágoston , András Némethi