scholarly journals ABOUT THE $\bar{\partial}$-EQUATION AT ISOLATED SINGULARITIES WITH REGULAR EXCEPTIONAL SET

2009 ◽  
Vol 20 (04) ◽  
pp. 459-489 ◽  
Author(s):  
JEAN RUPPENTHAL
Keyword(s):  
Necessary Conditions ◽  
Sufficient Condition ◽  
Isolated Singularity ◽  
Isolated Singularities ◽  
Exceptional Set ◽  
Analytic Variety ◽  
Stein Domain ◽  
Hölder Estimates

Let Y be a pure dimensional analytic variety in ℂn with an isolated singularity at the origin such that the exceptional set X of a desingularization of Y is regular. The main objective of the present paper is to present a technique which allows us to determine obstructions to the solvability of the [Formula: see text] equation in the L2, respectively L∞, sense on Y* = Y\{0} in terms of certain cohomology classes on X. More precisely, let Ω ⊂⊂ Y be a Stein domain with 0 ∈ Ω, Ω* = Ω\{0}. We give a sufficient condition for the solvability of the [Formula: see text] equation in the L2-sense on Ω*; and in the L∞ sense, if Ω is in addition strongly pseudoconvex. If Y is an irreducible cone, we also give some necessary conditions and obtain optimal Hölder estimates for solutions of the [Formula: see text] equation.

scholarly journals Invariants of topological relative right equivalences

2013 ◽  
Vol 155 (2) ◽  
pp. 307-315 ◽  
Author(s):  
IMRAN AHMED ◽  
MARIA APARECIDA SOARES RUAS ◽  
JOÃO NIVALDO TOMAZELLA
Keyword(s):  
Analytic Function ◽  
Milnor Number ◽  
Isolated Singularity ◽  
Isolated Singularities ◽  
Function Germ ◽  
Analytic Variety ◽  
Relative Version ◽  
Topological Invariance

AbstractLet (V,0) be the germ of an analytic variety in $\mathbb{C}^n$ and f an analytic function germ defined on V. For functions with isolated singularity on V, Bruce and Roberts introduced a generalization of the Milnor number of f, which we call Bruce–Roberts number, μBR(V,f). Like the Milnor number of f, this number shows some properties of f and V. In this paper we investigate algebraic and geometric characterizations of the constancy of the Bruce–Roberts number for families of functions with isolated singularities on V. We also discuss the topological invariance of the Bruce–Roberts number for families of quasihomogeneous functions defined on quasihomogeneous varieties. As application of the results, we prove a relative version of the Zariski multiplicity conjecture for quasihomogeneous varieties.

scholarly journals HOMOLOGICAL INDEX FOR 1-FORMS AND A MILNOR NUMBER FOR ISOLATED SINGULARITIES

2004 ◽  
Vol 15 (09) ◽  
pp. 895-905 ◽  
Author(s):  
W. EBELING ◽  
S. M. GUSEIN-ZADE ◽  
J. SEADE
Keyword(s):  
Complete Intersection ◽  
Milnor Number ◽  
Isolated Singularity ◽  
Isolated Singularities ◽  
Analytic Variety ◽  
Curve Singularities ◽  
Complex Analytic Variety ◽  
Arbitrary Curve

We introduce a notion of a homological index of a holomorphic 1-form on a germ of a complex analytic variety with an isolated singularity, inspired by Gómez-Mont and Greuel. For isolated complete intersection singularities it coincides with the index defined earlier by two of the authors. Subtracting from this index another one, called radial, we get an invariant of the singularity which does not depend on the 1-form. For isolated complete intersection singularities this invariant coincides with the Milnor number. We compute this invariant for arbitrary curve singularities and compare it with the Milnor number introduced by Buchweitz and Greuel for such singularities.

scholarly journals Noetherian properties in composite generalized power series rings

2020 ◽  
Vol 18 (1) ◽  
pp. 1540-1551
Author(s):  
Jung Wook Lim ◽  
Dong Yeol Oh
Keyword(s):  
Necessary Conditions ◽  
Sufficient Conditions ◽  
Commutative Rings ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Generalized Power Series ◽  
Ordered Monoid ◽  
Power Series Rings ◽  
Necessary And Sufficient ◽  
Equivalent Conditions

Abstract Let ({\mathrm{\Gamma}},\le ) be a strictly ordered monoid, and let {{\mathrm{\Gamma}}}^{\ast }\left={\mathrm{\Gamma}}\backslash \{0\} . Let D\subseteq E be an extension of commutative rings with identity, and let I be a nonzero proper ideal of D. Set \begin{array}{l}D+[\kern-2pt[ {E}^{{{\mathrm{\Gamma}}}^{\ast },\le }]\kern-2pt] := \left\{f\in [\kern-2pt[ {E}^{{\mathrm{\Gamma}},\le }]\kern-2pt] \hspace{0.15em}|\hspace{0.2em}f(0)\in D\right\}\hspace{.5em}\text{and}\\ \hspace{0.2em}D+[\kern-2pt[ {I}^{{\Gamma }^{\ast },\le }]\kern-2pt] := \left\{f\in [\kern-2pt[ {D}^{{\mathrm{\Gamma}},\le }]\kern-2pt] \hspace{0.15em}|\hspace{0.2em}f(\alpha )\in I,\hspace{.5em}\text{for}\hspace{.25em}\text{all}\hspace{.5em}\alpha \in {{\mathrm{\Gamma}}}^{\ast }\right\}.\end{array} In this paper, we give necessary conditions for the rings D+[\kern-2pt[ {E}^{{{\mathrm{\Gamma}}}^{\ast },\le }]\kern-2pt] to be Noetherian when ({\mathrm{\Gamma}},\le ) is positively ordered, and sufficient conditions for the rings D+[\kern-2pt[ {E}^{{{\mathrm{\Gamma}}}^{\ast },\le }]\kern-2pt] to be Noetherian when ({\mathrm{\Gamma}},\le ) is positively totally ordered. Moreover, we give a necessary and sufficient condition for the ring D+[\kern-2pt[ {I}^{{\Gamma }^{\ast },\le }]\kern-2pt] to be Noetherian when ({\mathrm{\Gamma}},\le ) is positively totally ordered. As corollaries, we give equivalent conditions for the rings D+({X}_{1},\ldots ,{X}_{n})E{[}{X}_{1},\ldots ,{X}_{n}] and D+({X}_{1},\ldots ,{X}_{n})I{[}{X}_{1},\ldots ,{X}_{n}] to be Noetherian.

scholarly journals Syarat Perlu dan Cukup untuk Keterbatasan Potensial Riesz di Ruang Morrey Klasik

2013 ◽  
Vol 14 (3) ◽  
pp. 227
Author(s):  
Mohammad Imam Utoyo ◽  
Basuki Widodo ◽  
Toto Nusantara ◽  
Suhariningsih Suhariningsih
Keyword(s):  
Characteristic Function ◽  
Morrey Space ◽  
Necessary Conditions ◽  
Riesz Potential ◽  
Necessary Condition ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Research Results ◽  
Necessary And Sufficient

This script was aimed to determine the necessary conditions for boundedness of Riesz potential in the classical Morrey space. If these results are combined with previous research results will be obtained the necessary and sufficient condition for boundedness of Riesz potential. This necessary condition is obtained through the use of characteristic function as one member of the classical Morrey space.

Xây dựng lược đồ chữ ký số an toàn từ các lược đồ định danh

2020 ◽  
Vol 8 (2) ◽  
pp. 27-33
Author(s):  
Võ Đình Linh
Keyword(s):  
Digital Signature ◽  
Necessary Conditions ◽  
Sufficient Condition ◽  
Signature Scheme ◽  
Identification Scheme ◽  
Identification Schemes ◽  
Digital Signature Scheme ◽  
Chosen Message Attack

 Tóm tắt— Trong tài liệu [3], khi trình bày về phương pháp xây dựng lược đồ chữ ký số dựa trên các lược đồ định danh chính tắc nhờ phép biến đổi Fiat-Shamir, tác giả đã chỉ ra “điều kiện đủ” để nhận được một lược đồ chữ ký số an toàn dưới tấn công sử dụng thông điệp được lựa chọn thích nghi là lược đồ định danh chính tắc phải an toàn dưới tấn công bị động. Tuy nhiên, tác giả của [3] chưa chỉ ra “điều kiện cần” đối với các lược đồ định danh chính tắc nhằm đảm bảo tính an toàn cho lược đồ chữ ký số được xây dựng. Do đó, trong bài báo này, chúng tôi hoàn thiện kết quả của [3] bằng việc chỉ ra điều kiện đủ đó cũng chính là điều kiện cần.Abstract— In [3], the author shows that, in order to the digital signature scheme Π' resulting from the Fiat-Shamir transform applied to a canonical identification scheme Π is existentially unforgeable under chosen-message attack then a “sufficient” condition is that the scheme Π has to be secure against a passive attack. However, the author of [3] has not shown the “necessary” conditions for the canonical identification schemes to ensure security of the digital signature scheme Π'. In this paper, we complete this result by showing that sufficient condition is also necessary. 

On the removability of isolated singular points for elliptic equations involving variable exponent

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Yongqiang Fu ◽  
Yingying Shan
Keyword(s):  
Singular Point ◽  
Elliptic Equations ◽  
Variable Exponent ◽  
Singular Points ◽  
Sufficient Condition ◽  
Variable Exponents ◽  
Isolated Singularities

AbstractIn this paper, we study the problem of removable isolated singularities for elliptic equations with variable exponents. We give a sufficient condition for removability of the isolated singular point for the equations in

scholarly journals Global Behaviors of a Chemostat Model with Delayed Nutrient Recycling and Periodically Pulsed Input

2010 ◽  
Vol 2010 ◽  
pp. 1-21 ◽  
Author(s):  
Kai Wang ◽  
Zhidong Teng ◽  
Fengqin Zhang
Keyword(s):  
Function Method ◽  
Global Attractivity ◽  
Necessary Conditions ◽  
Nutrient Recycling ◽  
Liapunov Function ◽  
Sufficient Condition ◽  
Chemostat Model ◽  
Dynamic Behaviors ◽  
Analysis Technique ◽  
Sufficient And Necessary Conditions

The dynamic behaviors in a chemostat model with delayed nutrient recycling and periodically pulsed input are studied. By introducing new analysis technique, the sufficient and necessary conditions on the permanence and extinction of the microorganisms are obtained. Furthermore, by using the Liapunov function method, the sufficient condition on the global attractivity of the model is established. Finally, an example is given to demonstrate the effectiveness of the results in this paper.

scholarly journals Constructing links of isolated singularities of polynomials ℝ4 → ℝ2

2019 ◽  
Vol 28 (01) ◽  
pp. 1950009 ◽  
Author(s):  
Benjamin Bode
Keyword(s):  
Isolated Singularity ◽  
Isolated Singularities ◽  
Nodal Set ◽  
Polynomial Formula

We show that if a braid [Formula: see text] can be parametrized in a certain way, then the previous work (B. Bode and M. R. Dennis, Constructing a polynomial whose nodal set is any prescribed knot or link, arXiv:1612.06328 ) can be extended to a construction of a polynomial [Formula: see text] with the closure of [Formula: see text] as the link of an isolated singularity of [Formula: see text], showing that the closure of [Formula: see text] is real algebraic. In particular, we prove that closures of squares of strictly homogeneous braids and certain lemniscate links are real algebraic. We also show that the constructed polynomials satisfy the strong Milnor condition, providing an explicit fibration of the complement of the closure of [Formula: see text] over [Formula: see text].

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