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We improve previous results by exhibiting a construction that contains all known examples. A suficient condition for the existence of robustly transitive maps displaying singularities on a certain large class of compact manifolds is given.

Dynamical Systems · Mathematics 2021-05-10 Juan Carlos Morelli

Models that provide experimentally testable violations of ordinary Quantum Mechanics have been recently proposed. These models are based on non-unitary time evolutions of density matrices that are generated by linear positive maps. We…

High Energy Physics - Theory · Physics 2009-10-30 F. Benatti , R. Floreanini

A proof using the theory of completely positive maps is given to the fact that if $A \in M_2$, or $A \in M_3$ has a reducing eigenvalue, then every bounded linear operator $B$ with $W(B) \subseteq W(A)$ has a dilation of the form $I \otimes…

Functional Analysis · Mathematics 2019-02-07 Chi-Kwong Li , Yiu-Tung Poon

This article provides sufficient conditions for positive maps on the Schatten classes $\mathcal J_{p}, 1\le p<\infty$ of bounded operators on a separable Hilbert space such that a corresponding Perron-Frobenius theorem holds. With…

Mathematical Physics · Physics 2007-05-23 Robert Schrader

Optimal maps, solutions to the optimal transportation problems, are completely determined by the corresponding c-convex potential functions. In this paper, we give simple sufficient conditions for a smooth function to be c-convex when the…

Differential Geometry · Mathematics 2010-06-22 Paul W. Y. Lee

In this article, we introduce a notion of an exponential matrix, which is a polynomial matrix with exponential properties, and a notion of an equivalence relation of two exponential matrices, and then we initiate to study classifying…

Representation Theory · Mathematics 2018-10-10 Ryuji Tanimoto

In this article, we investigate the relationship between the shadowing property of set-valued maps and their associated inverse limit systems. We show that if a set-valued map is expansive and open in the context of set-valued dynamics,…

Dynamical Systems · Mathematics 2025-01-28 Zhengyu Yin

This Letter provides necessary and sufficient conditions on the excitation and measurement pattern (EMP) that guarantee identifiability of a dynamical network that has the structure of a loop. The conditions are extremely simple in their…

Systems and Control · Electrical Eng. & Systems 2024-10-28 Eduardo Mapurunga , Michel Gevers , Alexandre Sanfelice Bazanella

We give sign conditions on the support and coefficients of a sparse system of d generalized polynomials in d variables that guarantee the existence of at least one positive real root, based on degree theory and Gale duality. In the case of…

Algebraic Geometry · Mathematics 2020-09-16 Frédéric Bihan , Alicia Dickenstein , Magalí Giaroli

We start from a parametrized system of $d$ generalized polynomial equations (with real exponents) for $d$ positive variables, involving $n$ generalized monomials with $n$ positive parameters. Existence and uniqueness of a solution for all…

Algebraic Geometry · Mathematics 2019-05-08 Stefan Müller , Josef Hofbauer , Georg Regensburger

This note describes necessary and sufficient conditions for a sequence of positive integers to be the degree sequence of a connected simple graph. Conditions are also given under which a sequence is necessarily connected i.e. the sequence…

Combinatorics · Mathematics 2015-12-19 Jonathan McLaughlin

We consider the convex set of ( unital ) positive ( completely ) maps from a $C^*$ algebra $\cla$ to a von-Neumann sub-algebra $\clm$ of $\clb(\clh)$, the algebra of bounded linear operators on a Hilbert space $\clh$ and study its extreme…

Operator Algebras · Mathematics 2015-07-31 Anilesh Mohari

We prove that all injective maps on positive complex matrices which preserve order and shrink spectrum are implemented by unitary or antiunitary conjugations. We show by counterexamples that all assumptions are indispensable. The result…

Functional Analysis · Mathematics 2022-04-26 Mateo Tomašević

It is shown that a graph parameter can be realized as the number of homomorphisms into a fixed (weighted) graph if and only if it satisfies two linear algebraic conditions: reflection positivity and exponential rank-connectivity. In terms…

Combinatorics · Mathematics 2007-05-23 M. Freedman , L. Lovasz , A. Schrijver

A factor of a graph is a spanning subgraph. Spectral sufficient conditions are provided via spectral radius and signless Laplacian spectral radius for graphs with (i) a matching of given size (particularly, $1$-factor) containing any given…

Combinatorics · Mathematics 2024-01-25 Jin Cai , Bo Zhou

We study k Kadison Schwarz (k KS) mappings on matrix algebras and derive explicit conditions ensuring the k KS property for two classes of maps parameterized by a single k-positive map.

Functional Analysis · Mathematics 2026-03-13 Farrukh Mukhamedov , Dariusz Chruściński

Suppose a map $\phi$ on the set of positive definite matrices satisfies $\det(A+B)=\det(\phi(A)+\phi(B))$. Then we have $${\rm tr}(AB^{-1}) = {\rm tr}(\phi(A){\phi(B)}^{-1}).$$ Through this viewpoint, we show that $\phi$ is of the form…

Rings and Algebras · Mathematics 2016-03-15 Huajun Huang , Chih-Neng Liu , Patricia Szokol , Ming-Cheng Tsai , Jun Zhang

In this paper, we provide a structure theorem and various characterizations of degradable strongly entanglement breaking maps on separable Hilbert spaces. In the finite dimensional case, we prove that unital degradable entanglement breaking…

Operator Algebras · Mathematics 2024-10-08 Repana Devendra , Gunjan sapra , K. Sumesh

A linear map $\Phi$ between matrix spaces is called cross-positive if it is positive on orthogonal pairs $(U,V)$ of positive semidefinite matrices in the sense that $\langle U,V\rangle:=\text{Tr}(UV)=0$ implies $\langle…

Functional Analysis · Mathematics 2025-11-14 Igor Klep , Klemen Šivic , Aljaž Zalar

In this paper, by reviewing the concept of subcovering and semicovering maps, we extend the notion of subcovering map to subsemicovering map. We present some necessary or sufficient conditions for a local homeomorphism to be a…

Algebraic Topology · Mathematics 2016-07-04 Majid Kowkabi , Behrooz Mashayekhy , Hamid Torabi