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Related papers: Exposed positive maps in M_4(C)

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We exhibit a new large class of $C^1$ open examples of robustly transitive maps displaying persistent critical points in the homotopy class of expanding endomorphisms acting on the two dimensional Torus and the Klein bottle.

Dynamical Systems · Mathematics 2024-01-30 Cristina Lizana , Wagner Ranter

We show that if $E$ is a closed convex set in $\mathbb C^n$ $(n>1)$ contained in a closed halfspace $H$ such that $E\cap bH$ is nonempty and bounded, then the concave domain $\Omega = \mathbb C^n\setminus E$ contains images of proper…

Complex Variables · Mathematics 2023-08-07 Barbara Drinovec Drnovsek , Franc Forstneric

For A a separable unital C*-algebra and M a separable McDuff II_1-factor, we show that the space Hom_w(A,M) of weak approximate unitary equivalence classes of unital *-homomorphisms A \rightarrow M may be considered as a closed, bounded,…

Operator Algebras · Mathematics 2015-12-02 Scott Atkinson

We consider graphs E which have been obtained by adding one or more sinks to a fixed directed graph G. We classify the C*-algebra of E up to a very strong equivalence relation, which insists, loosely speaking, that C*(G) is kept fixed. The…

Operator Algebras · Mathematics 2007-05-23 Iain Raeburn , Mark Tomforde , Dana P. Williams

The properties of convex pentagonal monotiles in the 15 Type families and their tilings are summarized. The Venn diagrams of the 15 Type families are also shown.

History and Overview · Mathematics 2026-01-30 Teruhisa Sugimoto

We present an algebra related to the Coxeter group of type F4 which can be viewed as the Brauer algebra of type F4 and is obtained as a subalgebra of the Brauer algebra of type E6. We also describe some properties of this algebra.

Representation Theory · Mathematics 2012-06-29 Shoumin Liu

This expository article gives a survey of matrix convex sets, a natural generalization of convex sets to the noncommutative (dimension-free) setting, with a focus on their extreme points. Mirroring the classical setting, extreme points play…

Functional Analysis · Mathematics 2025-05-29 Eric Evert , Benjamin Passer , Tea Štrekelj

An orientation preserving diffeomorphism over a surface embedded in a 4-manifold is called extendable, if this diffeomorphism is a restriction of an orientation preserving diffeomorphism on this 4-manifold. In this paper, we investigate…

Geometric Topology · Mathematics 2014-10-01 Susumu Hirose

The utility of a matrix satisfying the Strong Spectral Property has been well established particularly in connection with the inverse eigenvalue problem for graphs. More recently the class of graphs in which all associated symmetric…

In this paper, some subclasses of block graphs are considered in order to analyze Fiedler vector of its members. Two families of block graphs with cliques of fixed size, the block-path and block-starlike graphs, are introduced. Cases A and…

Discrete Mathematics · Computer Science 2021-06-30 Daniel Felisberto Traciná Filho , Claudia Marcela Justel

We show that closed, connected 4-manifolds up to connected sum with copies of the complex projective plane are classified in terms of the fundamental group, the orientation character and an extension class involving the second homotopy…

Geometric Topology · Mathematics 2023-04-13 Daniel Kasprowski , Mark Powell , Peter Teichner

Confocal conics form an orthogonal net. Supplementing this net with one of the following: 1) the net of Cartesian coordinate lines aligned along the principal axes of conics, 2) the net of Apollonian pencils of circles whose foci coincide…

Differential Geometry · Mathematics 2019-12-30 Sergey I. Agafonov

We introduce an invariant of tuples of commutative diffeomorphisms on a 4-manifold using families of Seiberg-Witten equations. This is a generalization of Ruberman's invariant of diffeomorphisms defined using 1-parameter families of…

Differential Geometry · Mathematics 2019-07-03 Hokuto Konno

We study the exceptional loci of birational (bimeromorphic) contractions of a hyperk\"ahler manifold $M$. Such a contraction locus is the union of all minimal rational curves in a collection of cohomology classes which are orthogonal to a…

Algebraic Geometry · Mathematics 2021-09-20 Ekaterina Amerik , Misha Verbitsky

We show the correspondence between left invariant flat projective structures on Lie groups and certain prehomogeneous vector spaces. Moreover by using the classification theory of prehomogeneous vector spaces, we classify complex Lie groups…

Differential Geometry · Mathematics 2014-06-16 Hironao Kato

We conjecture that finite graphs with positive Cheeger constant admit a spanning subgraph with positive Cheeger constant and girth proportional to the diameter. We prove this conjecture for regular expander graphs with large expansion. Our…

Combinatorics · Mathematics 2021-12-04 Itai Benjamini , Mikolaj Fraczyk , Gabor Kun

In this paper, we show the convexity of the image of a moment map on a transverse symplectic manifold equipped with a torus action under a certain condition. We also study properties of moment maps in the case of transverse K\"ahler…

Complex Variables · Mathematics 2015-09-15 Hiroaki Ishida

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

In this paper we characterize Moore-Penrose inverses of Gram matrices leaving a cone invariant in an indefinite inner product space using indefinite matrix multiplication. This characterization includes the acuteness (or obtuseness) of…

Functional Analysis · Mathematics 2015-07-21 K. Appi Reddy , T. Kurmayya

A partial description of the structure of positive unital maps $\phi: M_2(\bC) \to M_{n+1}(\bC)$ ($n\geq 2$) is given.

Functional Analysis · Mathematics 2007-05-23 Wladyslaw A. Majewski , Marcin Marciniak