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Let $H$ and $K$ be (finite or infinite dimensional) complex Hilbert spaces. A characterization of positive completely bounded normal linear maps from ${\mathcal B}(H)$ into ${\mathcal B}(K)$ is given, which particularly gives a…

Quantum Physics · Physics 2010-08-24 Jinchuan Hou

In this paper we develop in detail the geometric constructions that lead to many uniqueness results for the determination of polyhedral sets, typically scatterers, by a finite minimal number of measurements. We highlight how unique…

Analysis of PDEs · Mathematics 2023-10-10 Luca Rondi

This paper studies the class of stochastic maps, or channels, whose action (when tensored with the identity) on an entangled state always yields a separable state. Such maps have a canonical form introduced by Holevo. Such maps are called…

Quantum Physics · Physics 2009-11-10 Michael Horodecki , Peter W. Shor , Mary Beth Ruskai

For an $n$-vertex graph $G$, let $z(G;k)$ denote the number of zero forcing sets of size $k$. A conjecture of Boyer et al. asserts that the path $P_n$ maximizes these numbers coefficientwise among all $n$-vertex graphs; equivalently, the…

Discrete Mathematics · Computer Science 2026-05-12 Samuel German

By using of a special reduction way of density matrices, in this Letter we find the entanglement between two bunches of particles, its measure can be represented by the entanglement of formation.

Quantum Physics · Physics 2007-05-23 Zai-Zhe Zhong

It is shown that for a constant $t\in \mathbb{N}$, every simple topological graph on $n$ vertices has $O(n)$ edges if it has no two sets of $t$ edges such that every edge in one set is disjoint from all edges of the other set (i.e., the…

Combinatorics · Mathematics 2015-08-25 Andres J. Ruiz-Vargas , Andrew Suk , Csaba D. Tóth

Employing a recently proposed separability criterion we develop analytical lower bounds for the concurrence and for the entanglement of formation of bipartite quantum systems. The separability criterion is based on a nondecomposable…

Quantum Physics · Physics 2007-05-23 Heinz-Peter Breuer

A thrackle is a drawing of a graph in which each pair of edges meets precisely once. Conway's Thrackle Conjecture asserts that a thrackle drawing of a graph on the plane cannot have more edges than vertices. We prove the Conjecture for…

Combinatorics · Mathematics 2023-06-22 Grace Misereh , Yuri Nikolayevsky

A set of n segments in the plane may form a Euclidean TSP tour, a tree, or a matching, among others. Optimal TSP tours as well as minimum spanning trees and perfect matchings have no crossing segments, but several heuristics and…

Computational Geometry · Computer Science 2025-01-22 Guilherme D. da Fonseca , Yan Gerard , Bastien Rivier

Through careful analysis of types inspired by [AGTW21] we characterize a notion of definable compactness for definable topologies in general o-minimal structures, generalizing results from [PP07] about closed and bounded definable sets in…

Logic · Mathematics 2021-11-09 Pablo Andújar Guerrero

A graph is chordal if every cycle of length at least four contains a chord, that is, an edge connecting two nonconsecutive vertices of the cycle. Several classical applications in sparse linear systems, database management, computer vision,…

Data Structures and Algorithms · Computer Science 2016-12-07 David Bergman , Carlos H. Cardonha , Andre A. Cire , Arvind U. Raghunathan

We establish maximal trees and graphs for the difference of average distance and proximity proving thus the corresponding conjecture posed in [4]. We also establish maximal trees for the difference of average eccentricity and remoteness and…

Combinatorics · Mathematics 2020-10-22 Jelena Sedlar

We complete characterization of bijections preserving commutators (PC-maps) in the group of unitriangular matrices $UT(n,F)$ over a field $F$, where $n$ is a natural number or infinity. PC-maps were recently described up to almost identity…

Group Theory · Mathematics 2015-05-26 Waldemar Holubowski , Alexei Stepanov

We show that for every $n \in \mathbb N$ there is a collection of points $p_1, \ldots, p_n$ and lines $\ell_1, \ldots, \ell_n$ in the unit square such that for any $i$ we have $p_i \in \ell_i$ and the distance from $p_i$ to any other line…

Combinatorics · Mathematics 2025-11-14 Alexander Logunov , Dmitrii Zakharov

We provide a framework for a perturbative evaluation of the reduced density matrix. The method is based on a path integral in the analytically continued spacetime. It suggests an alternative to the holographic and `standard' replica trick…

High Energy Physics - Theory · Physics 2015-06-19 Vladimir Rosenhaus , Michael Smolkin

By finding orthogonal representation for a family of simple connected called $\delta$-graphs it is possible to show that $\delta$-graphs satisfy delta conjecture. An extension of the argument to graphs of the form…

Combinatorics · Mathematics 2018-06-20 Pedro Díaz Navarro

A decomposition of a graph is a set of subgraphs whose edges partition those of $G$. The 3-decomposition conjecture posed by Hoffmann-Ostenhof in 2011 states that every connected cubic graph can be decomposed into a spanning tree, a…

Combinatorics · Mathematics 2022-11-08 Oliver Bachtler , Sven O. Krumke

We demonstrate that when a graph exhibits a specific type of symmetry, it satisfies the Union Closed Conjecture(UCC). Additionally, we show that certain graph classes, such as Cylindrical Grid Graphs and Torus Grid Graphs also satisfy the…

Combinatorics · Mathematics 2024-11-12 Nived J M

We continue the study of entanglement entropy for a QFT through a perturbative expansion of the path integral definition of the reduced density matrix. The universal entanglement entropy for a CFT perturbed by a relevant operator is…

High Energy Physics - Theory · Physics 2015-06-23 Vladimir Rosenhaus , Michael Smolkin

The pentagram map takes a planar polygon $P$ to a polygon $P'$ whose vertices are the intersection points of consecutive shortest diagonals of $P$. This map is known to interact nicely with Poncelet polygons, i.e. polygons which are…

Exactly Solvable and Integrable Systems · Physics 2022-02-14 Anton Izosimov