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One possibility of defining a quantum R\'enyi $\alpha$-divergence of two quantum states is to optimize the classical R\'enyi $\alpha$-divergence of their post-measurement probability distributions over all possible measurements (measured…

Quantum Physics · Physics 2023-01-18 Milán Mosonyi , Fumio Hiai

Arbitrarily small changes in the commutation relations suffice to transform the usual singular quantum theories into regular quantum theories. This process is an extension of canonical quantization that we call general quantization. Here we…

Quantum Physics · Physics 2007-05-23 Mohsen Shiri-Garakani , David Ritz Finkelstein

The geometry of Hamiltonian's eigenstates is encoded in the quantum geometric tensor (QGT). It contains both the Berry curvature, central to the description of topological matter and the quantum metric. So far the full QGT has been measured…

Mesoscale and Nanoscale Physics · Physics 2021-09-08 Qing Liao , Charly Leblanc , Jiahuan Ren , Feng Li , Yiming Li , Dmitry Solnyshkov , Guillaume Malpuech , Jiannian Yao , Hongbing Fu

Quantum Mechanics places limits on achievable transverse beam spot sizes of particle accelerators. We estimate this limit for a linear collider to be \Delta x > \hbar c f/E\delta_0 where f is the final focal length, E the beam energy, and…

High Energy Physics - Phenomenology · Physics 2007-05-23 Christopher T. Hill

We prove the large deviations principle for empirical Bures-Wasserstein barycenters of independent, identically-distributed samples of covariance matrices and covariance operators. As an application, we explore some consequences of our…

Probability · Mathematics 2024-09-18 Adam Quinn Jaffe , Leonardo V. Santoro

The trace distance between two quantum states, $\rho$ and $\sigma$, is an operationally meaningful quantity in quantum information theory. However, in general it is difficult to compute, involving the diagonalization of $\rho - \sigma$. In…

Quantum Physics · Physics 2019-08-07 Patrick J. Coles , M. Cerezo , Lukasz Cincio

Suppose $g_t$ is a $1$-parameter $\mathrm{Ad}$-diagonalizable subgroup of a Lie group $G$ and $\Gamma < G$ is a lattice. We study the dimension of bounded and divergent orbits of $g_t$ emanating from a class of curves lying on leaves of the…

Dynamical Systems · Mathematics 2020-03-27 Osama Khalil

We reprove the well known fact that the energy distance defines a metric on the space of Borel probability measures on a Hilbert space with finite first moment by a new approach, by analyzing the behavior of the Gaussian kernel on Hilbert…

Functional Analysis · Mathematics 2021-02-02 Jean Carlo Guella

One-dimensional unitary scattering controlled by non-Hermitian (typically, ${\cal PT}$-symmetric) quantum Hamiltonians $H\neq H^\dagger$ is considered. Treating these operators via Runge-Kutta approximation, our three-Hilbert-space…

Quantum Physics · Physics 2009-08-31 Miloslav Znojil

Combining gravity with quantum theory is still work in progress. On the one hand, classical gravity, is the geometry of space-time determined by the energy-momentum tensor of matter and the resulting nonlinear equations; on the other hand,…

Quantum Physics · Physics 2024-01-26 P. Gusin , D. Burys , A. Radosz

We continue our study of the quantum mechanical motion in the $x^2y^2$ potentials for $n=2,3$, which arise in the spatially homogeneous limit of the Yang-Mills (YM) equations. In the present paper, we develop a new approach to the…

Quantum Physics · Physics 2009-11-11 Sergei G. Matinyan , Berndt Müller

An algebraic analysis framework for quantum calculus is proposed. The quantum derivative operator $D_{\tau ,\sigma}$ is based on two commuting bijections $\tau$ and $\sigma$ defined on an arbitrary set $M$ equipped with a tension structure…

Quantum Algebra · Mathematics 2010-12-30 Piotr Multarzynski

The superfluid weight of a generic lattice model with attractive Hubbard interaction is computed analytically in the isolated band limit within the generalized random phase approximation. Time-reversal symmetry, spin rotational symmetry,…

Superconductivity · Physics 2024-05-20 Minh Tam , Sebastiano Peotta

A function $f: \mathbb{Z} \to \mathbb{Q}^n$ is a $c$-quasihomomorphism if the Hamming distance between $f(x+y)$ and $f(x)+f(y)$ is at most $c$ for all $x,y \in \mathbb{Z}$. We show that any $c$-quasihomomorphism has distance at most some…

Combinatorics · Mathematics 2022-04-19 Jan Draisma , Rob H. Eggermont , Tim Seynnaeve , Nafie Tairi , Emanuele Ventura

In this paper, we generalize the notions of centroids and barycenters to the broad class of information-theoretic distortion measures called Bregman divergences. Bregman divergences are versatile, and unify quadratic geometric distances…

Computational Geometry · Computer Science 2007-11-22 Frank Nielsen , Richard Nock

Quantum tomography has become an indispensable tool in order to compute the density matrix $\rho$ of quantum systems in Physics. Recently, it has further gained importance as a basic step to test entanglement and violation of Bell…

High Energy Physics - Phenomenology · Physics 2024-10-04 Alexander Bernal

This work studies the convergence and finite sample approximations of entropic regularized Wasserstein distances in the Hilbert space setting. Our first main result is that for Gaussian measures on an infinite-dimensional Hilbert space,…

Machine Learning · Statistics 2021-02-16 Minh Ha Quang

We derive fundamental lower bounds on the performance of optical metrology and communication systems in a Bayesian framework. The derivation uses classical rate-distortion theory in conjunction with bounds on the capacity to transmit…

Quantum Physics · Physics 2018-09-24 Ranjith Nair

We describe Wasserstein isometries of the quantum bit state space with respect to distinguished cost operators. We derive a Wigner-type result for the cost operator involving all the Pauli matrices: in this case, the isometry group consists…

Mathematical Physics · Physics 2024-08-13 György Pál Gehér , József Pitrik , Tamás Titkos , Dániel Virosztek

The necessity of complex numbers in quantum mechanics has long been debated. This paper develops a real Kahler space formulation of quantum mechanics [19], asserting equivalence to the standard complex Hilbert space framework. By mapping…

Quantum Physics · Physics 2025-06-10 Irina Aref'eva , Igor Volovich