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Related papers: Numerical shadow and geometry of quantum states

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We provide a new perspective on shadow tomography by demonstrating its deep connections with the general theory of measurement frames. By showing that the formalism of measurement frames offers a natural framework for shadow tomography --…

In previously exhibited hidden variable models of quantum state preparation and measurement, the number of continuous hidden variables describing the actual state of a single realization is never smaller than the quantum state manifold…

Quantum Physics · Physics 2011-03-23 Alberto Montina

The geometric formulation of quantum mechanics is a very interesting field of research which has many applications in the emerging field of quantum computation and quantum information, such as schemes for optimal quantum computers. In this…

Quantum Physics · Physics 2014-04-24 Ole Andersson , Hoshang Heydari

Convex support, the mean values of a set of random variables, is central in information theory and statistics. Equally central in quantum information theory are mean values of a set of observables in a finite-dimensional C*-algebra A, which…

Mathematical Physics · Physics 2016-05-17 Stephan Weis

This paper presents an introduction to geometric representations of quantum states in which each distinct quantum state, pure and mixed, corresponds to a unique point in a Euclidean space. Beginning with a review of some underappreciated…

Quantum Physics · Physics 2026-02-17 Athanasios Kostikas , Yaroslav Valchyshen , Paul Cadden-Zimansky

We discuss the concept of the shadow boundary of a centrally symmetric convex ball $K$ (actually being the unit ball of a Minkowski normed space) with respect to a direction ${\bf x}$ of the Euclidean n-space $R^n$. We introduce the concept…

Metric Geometry · Mathematics 2007-06-21 Akos G. Horvath

We explore the characteristics of shadows for a general class of spherically symmetric, static spacetimes, which may arise in general relativity or in modified theories of gravity. The chosen line element involves a sum (with constant but…

General Relativity and Quantum Cosmology · Physics 2024-03-19 Md. Golam Mafuz , Rishank Diwan , Soumya Jana , Sayan Kar

We consider the space M of NxN matrices as a reduced quantum plane and discuss its geometry under the action and coaction of finite dimensional quantum groups (a quotient of U_q(SL(2)), q being an N-th root of unity, and its dual). We also…

Mathematical Physics · Physics 2007-05-23 R. Coquereaux , A. O. Garcia , R. Trinchero

They proved several properties and introduced some inequalities. We continue with the study of this generalized numerical radius and we develop diverse inequalities involving w_N. We also study particular cases with a fixed N(.), for…

Functional Analysis · Mathematics 2020-06-29 Tamara Bottazzi , Cristian Conde

Conventional quantum computing entails a geometry based on the description of an n-qubit state using 2^{n} infinite precision complex numbers denoting a vector in a Hilbert space. Such numbers are in general uncomputable using any…

Quantum Physics · Physics 2015-06-05 Andrew J. Hanson , Gerardo Ortiz , Amr Sabry , Yu-Tsung Tai

We introduce the problem of *shadow tomography*: given an unknown $D$-dimensional quantum mixed state $\rho$, as well as known two-outcome measurements $E_{1},\ldots,E_{M}$, estimate the probability that $E_{i}$ accepts $\rho$, to within…

Quantum Physics · Physics 2018-11-14 Scott Aaronson

We develop a version of quantum mechanics that can handle nonassociative algebras of observables and which reduces to standard quantum theory in the traditional associative setting. Our algebraic approach is naturally probabilistic and is…

Quantum Physics · Physics 2024-05-10 Peter Schupp , Richard J. Szabo

We reconsider the geometry of pure and mixed states in a finite quantum system. The rangesof eigenvalues of the density matrices delimit a regular simplex (Hypertetrahedron TN) in any dimension N; the polytope isometry group is the…

Quantum Physics · Physics 2009-11-13 Luis J. Boya , Kuldeep Dixit

Quantum information geometry studies families of quantum states by means of differential geometry. A new approach is followed with the intention to facilitate the introduction of a more general theory in subsequent work. To this purpose,…

Mathematical Physics · Physics 2018-08-01 Jan Naudts

We analyse orthogonal bases in a composite $N\times N$ Hilbert space describing a bipartite quantum system and look for a basis with optimal single-sided mutual state distinguishability. This condition implies that in each subsystem the…

Quantum Physics · Physics 2021-04-28 Jakub Czartowski , Karol Życzkowski

We introduce a variational scheme inspired by classical shadow tomography to compute ground state correlations of quantum spin Hamiltonians. Shadow tomography allows for efficient reconstruction of expectation values of arbitrary…

Quantum Physics · Physics 2025-08-04 Pierre-Gabriel Rozon , Kartiek Agarwal

Topological and geometrical properties of the set of mixed quantum states in the N-dimensional Hilbert space are analysed. Assuming that the corresponding classical dynamics takes place on the sphere we use the vector SU(2) coherent states…

Quantum Physics · Physics 2009-11-06 Karol Zyczkowski , Wojciech Slomczynski

The application of geometry to physics has provided us with new insightful information about many physical theories such as classical mechanics, general relativity, and quantum geometry (quantum gravity). The geometry also plays an…

Quantum Physics · Physics 2015-06-19 Hoshang Heydari

States of a quantum mechanical system are represented by rays in a complex Hilbert space. The space of rays has, naturally, the structure of a K\"ahler manifold. This leads to a geometrical formulation of the postulates of quantum mechanics…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Abhay Ashtekar , Troy A. Schilling

We analyze several product measures in the space of mixed quantum states. In particular we study measures induced by the operation of partial tracing. The natural, rotationally invariant measure on the set of all pure states of a N x K…

Quantum Physics · Physics 2009-11-06 Karol Zyczkowski , Hans-Juergen Sommers