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Related papers: Reflection positivity and spectral theory

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Let $V$ be a vector space endowed with a non-degenerate quadratic form $Q$. If the base field $\mathbb{F}$ is different from $\mathbb{F}_2$, it is known that every isometry can be written as a product of reflections. In this article, we…

Group Theory · Mathematics 2021-03-04 Jon McCammond , Giovanni Paolini

We introduce a real-parameter refinement of the classical integer hierarchies underlying Schmidt number, block-positivity, and $k$-positivity for maps between matrix algebras. Starting from a compact family of $\alpha$-admissible unit…

Functional Analysis · Mathematics 2026-02-16 Mohsen Kian

Let X be a Hilbert bimodule over a C*-algebra A and $O_X= A \rtimes_X \Z$. Using a finite section method we construct a sequence of completely positive contractions factoring through matrix algebras over A which act on $s_{\xi} s_{\eta}^*$…

Operator Algebras · Mathematics 2008-04-04 Adam Skalski , Joachim Zacharias

The main aim of this paper is to generalize the classical concept of positive operator, and to develop a general extension theory, which overcomes not only the lack of a Hilbert space structure, but also the lack of a normable topology. The…

Functional Analysis · Mathematics 2018-10-08 Zsigmond Tarcsay , Tamás Titkos

For multiqubit density operators in a suitable tensorial basis, we show that a number of nonunitary operations used in the detection and synthesis of entanglement are classifiable as reflection symmetries, i.e., orientation changing…

Quantum Physics · Physics 2018-08-30 Claudio Altafini , Timothy F. Havel

A simple condition is given that is sufficient to determine whether a measure that is absolutely continuous with respect to a Gau{\ss}ian measure on the space of distributions is reflection positive. It readily generalises conventional…

Mathematical Physics · Physics 2024-10-08 Jobst Ziebell

We aim in this manuscript to describe a specific notion of geometric positivity that manifests in cohomology rings associated to the flag variety $G/B$ and, in some cases, to subvarieties of $G/B$. We offer an exposition on the the…

Algebraic Geometry · Mathematics 2023-06-27 Rebecca Goldin

The starting point of this paper is that a spectral method is essentially a combination of an orthonormal basis of the underlying Hilbert space with Galerkin conditions. The choice of an orthonormal basis depends on a number of desirable…

Numerical Analysis · Mathematics 2026-03-13 Arieh Iserles , Marcus Webb

In this note, we show that the spectral theorem, has two representations; the Stone-von Neumann representation and one based on the polar decomposition of linear operators, which we call the deformed representation. The deformed…

Mathematical Physics · Physics 2012-11-02 Tepper L Gill , Daniel Williams

A lighting-based multispectral imaging system using an RGB camera and a projector is one of the most practical and low-cost systems to acquire multispectral observations for estimating the scene's spectral reflectance information. However,…

Image and Video Processing · Electrical Eng. & Systems 2020-12-21 Hironori Hidaka , Yusuke Monno , Masatoshi Okutomi

The Riemann-Hilbert approach is extended to discuss the well-posedness of the nonlinear Schr\"odinger-Gerdjikov-Ivanon equation. The Lipschitz continuity of potential in $H^{2}(\mathbb{R})\cap H^{1,1}(\mathbb{R})$ to scattering data is…

Analysis of PDEs · Mathematics 2025-11-25 Sucai Niu , Junyi Zhu

The biduality and reflexivity theorems are known to hold for projective varieties defined over fields of characteristic zero, and to fail in positive characteristic. In this article, we construct a notion of reflexivity and biduality in…

Algebraic Geometry · Mathematics 2020-04-08 Aristides Kontogeorgis , Georgios Petroulakis

We prove a conjecture of Dale Peterson on positivity in the multiplication in the T-equivariant cohomology of the flag variety. The theorem follows from a more general positivity result about the equivariant cohomology of varieties with…

Algebraic Geometry · Mathematics 2007-05-23 William Graham

In consideration of the integral transform whose kernel arises as an oscillatory solution of certain second-order linear differential equation, its positivity is investigated on the basis of Sturm's theory. As applications, positivity…

Classical Analysis and ODEs · Mathematics 2023-11-09 Yong-Kum Cho , Seok-Young Chung , Young Woong Park

In a previous work I constructed R-negative scissors states in the Two-Rotors Model in which the rotors are two-sided classical bodies. Such states have |K| = 1; 0 components and negative space parity. Here I extend this work including…

Nuclear Theory · Physics 2021-06-30 Fabrizio Palumbo

Let R: V x V -> V x V be a Hecke type solution of the quantum Yang-Baxter equation (a Hecke symmetry). Then, the Hilbert-Poincre' series of the associated R-exterior algebra of the space V is a ratio of two polynomials of degree m…

Quantum Algebra · Mathematics 2007-05-23 D. Gurevich , P. Pyatov , P. Saponov

We report a unified representation of the spatial and angular Goos-Hanchen and Imbert-Fedorov shifts that occur when a light beam reflects from a plane interface. We thus reveal the dual nature of spatial and angular shifts in optical beam…

Optics · Physics 2015-05-14 A. Aiello , M. Merano , J. P. Woerdman

We study functions f : (a,b) ---> R on open intervals in R with respect to various kinds of positive and negative definiteness conditions. We say that f is positive definite if the kernel f((x + y)/2) is positive definite. We call f…

Functional Analysis · Mathematics 2016-12-20 P. Jorgensen , K. -H. Neeb , G. Olafsson

As a prototype of an evolution equation we consider the Schr\"odinger equation i (d/dt) \Psi(t) = H \Psi(t), H = H_0 + V(x) for the Hilbert space valued function \Psi(.) which describes the state of the system at time t in space dimension…

Mathematical Physics · Physics 2016-09-07 Volker Enss

We reflect on the notions of positivity and square roots. We review many examples which underline our thesis that square roots of positive maps related to *-algebras are Hilbert modules. As a result of our considerations we discuss…

Operator Algebras · Mathematics 2017-08-23 Michael Skeide