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Making use of the method of subordination chains, we obtain some sufficient conditions for the univalence of an integral operator. In particular, as special cases, our results imply certain known univalence criteria. A refinement to a…

Complex Variables · Mathematics 2013-05-01 Halit Orhan , Dorina Răducanu , Murat Çağlar

We prove the determinant connectivity matrix formula. Mathematically, the proof introduces novel techniques based on an algebraic approach and connectivity properties. Although this is the second part of a previous paper and has its…

Rings and Algebras · Mathematics 2016-03-22 Juan Manuel Burgos

Let G be a block matrix function with one diagonal block A being positive definite and the off diagonal blocks complex conjugates of each other. Conditions are obtained for G to be factorable (in particular, with zero partial indices) in…

Functional Analysis · Mathematics 2018-03-29 Ilya M. Spitkovsky , Anatoly F. Voronin

We establish a necessary and sufficient condition for a normal subgroup of a finite group to be a subgroup perfect code.

Combinatorics · Mathematics 2025-05-08 Masoumeh Koohestani , Doost Ali Mojdeh , Mohsen Ghasemi , Hassan Khodaiemehr

We establish a sufficient condition for a finitely generated pro-$p$ group to be accessible in terms of finite generation of the module of ends.

Group Theory · Mathematics 2020-07-16 Gareth Wilkes

Let A be a positive operator in an infinite sigma-finite von Neumann factor M and let B_j be a sequence of positive elements in M. We give sufficient conditions for decomposing A into a sum of elements C_j equivalent to B_j for all j ( C…

Operator Algebras · Mathematics 2015-12-31 Catalin Dragan , Victor Kaftal

We provide a sufficient condition for solvability of a system of real quadratic equations $p_i(x)=y_i$, $i=1, \ldots, m$, where $p_i: {\mathbb R}^n \longrightarrow {\mathbb R}$ are quadratic forms. By solving a positive semidefinite…

Optimization and Control · Mathematics 2021-10-05 Alexander Barvinok , Mark Rudelson

A necessary and sufficient compactness criterion in Schauder Spaces is proved.

Functional Analysis · Mathematics 2023-06-27 M. Lanza de Cristoforis

Under some mild regularity on the normalizing sequence, we obtain necessary and sufficient conditions for the Strong Law of Large Numbers for (symmetrized) U-statistics. We also obtain nasc's for the a.s. convergence of series of an…

Probability · Mathematics 2014-11-17 Rafał Latała , Joel Zinn

We give the first algorithm for Matrix Completion whose running time and sample complexity is polynomial in the rank of the unknown target matrix, linear in the dimension of the matrix, and logarithmic in the condition number of the matrix.…

Machine Learning · Computer Science 2014-07-16 Moritz Hardt , Mary Wootters

In this article we prove a necessary and a sufficient condition for a finite subset of the special linear group to be dominated. These conditions are purely geometric in nature, as they only involve the trace and the eigenvectors of the…

Dynamical Systems · Mathematics 2026-05-11 Argyrios Christodoulou

This survey is devoted to necessary and suffcient conditions for a rational number to be representable by a Cantor series. Necessary and suffcient conditions are formulated for the case of an arbitrary sequence $(q_k)$.

Number Theory · Mathematics 2023-06-22 Symon Serbenyuk

We provide necessary and sufficient conditions for separability of mixed states. As a result we obtain a simple criterion of separability for $2\times2$ and $2\times3$ systems. Here, the positivity of the partial transposition of a state is…

Quantum Physics · Physics 2009-10-30 Michal Horodecki , Pawel Horodecki , Ryszard Horodecki

By definition, admissible matrix groups are those that give rise to a wavelet-type inversion formula. This paper investigates necessary and sufficient admissibility conditions for abelian matrix groups. We start out by deriving a block…

Functional Analysis · Mathematics 2011-04-12 Joaquim Bruna , Julià Cufí , Hartmut Führ , Margarida Miró

Necessary and sufficient condition is given for a set $A\subset R^1$ to be a subset of the critical values set for a $C^k$ function $f:R^m \to R^1$.

Classical Analysis and ODEs · Mathematics 2007-05-23 Azat Ainouline

This paper is concerned with the factorization and equivalence problems of multivariate polynomial matrices. We present some new criteria for the existence of matrix factorizations for a class of multivariate polynomial matrices, and obtain…

Symbolic Computation · Computer Science 2020-10-15 Dong Lu , Dingkang Wang , Fanghui Xiao

In the present paper and as an application of Roth's theorem concerning the rational approximation of algebraic numbers, we give a sufficient condition that will assure us that a series of positive rational terms is a transcendental number.…

Number Theory · Mathematics 2023-01-18 Fedoua Sghiouer , Kacem Belhroukia , Ali Kacha

Since the 1970s there has been a rich theory of equilibrium states over shift spaces associated to H\"older-continuous real-valued potentials. The construction of equilibrium states associated to matrix-valued potentials is much more…

Dynamical Systems · Mathematics 2016-12-07 Ian D. Morris

The following theorem is proved: Suppose $M = (a_{i,j})$ be a $k \times k$ matrix with positive entries and $a_{i,j}a_{i+1,j+1} > 4\cos ^2 \frac{\pi}{k+1} a_{i,j+1}a_{i+1,j} \quad (1 \leq i \leq k-1, 1 \leq j \leq k-1).$ Then $\det M > 0 .$…

Rings and Algebras · Mathematics 2007-05-23 Olga M. Katkova , Anna M. Vishnyakova

The necessary and sufficient conditions for differentiability of a function of several real variables stated and proved and its ramifications discussed.

Classical Analysis and ODEs · Mathematics 2007-05-23 R. P. Venkataraman