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We use polarization operators known from quantum theory of angular momentum to expand the $N \times N$ dimensional density operators. Thereby, we construct generalized Bloch vectors representing density matrices. We study their properties…

Quantum Physics · Physics 2007-05-23 Stanislaw Kryszewski , Mateusz Zachcial

We introduce a novel set-intersection operator called `most-intersection' based on the logical quantifier `most', via natural density of countable sets, to be used in determining the majority characteristic of a given countable (possibly…

General Mathematics · Mathematics 2021-06-24 Ahmet Çevik , Selçuk Topal

Relativistic quantum systems that admit scattering experiments are quantitatively described by effective field theories, where $S$-matrix kinematics and symmetry considerations are encoded in the operator spectrum of the EFT. In this paper…

High Energy Physics - Theory · Physics 2017-11-22 Brian Henning , Xiaochuan Lu , Tom Melia , Hitoshi Murayama

Density based representations of atomic environments that are invariant under Euclidean symmetries have become a widely used tool in the machine learning of interatomic potentials, broader data-driven atomistic modelling and the…

We provide a description of interacting quantum fields in terms of density matrices for any occupation numbers in Fock space in a momentum basis. As a simple example, we focus on a real scalar field interacting with another real scalar…

High Energy Physics - Theory · Physics 2023-06-09 Christian Käding , Mario Pitschmann

The probability density function of a probability distribution is a fundamental concept in probability theory and a key ingredient in various widely used machine learning methods. However, the necessary framework for compiling probabilistic…

Programming Languages · Computer Science 2019-03-14 Sooraj Bhat , Johannes Borgström , Andrew D. Gordon , Claudio Russo

Observed clusters should be modelled by considering the distribution function to be a random variable that quantifies the degree of excitation of the system's normal modes. A system of canonical coordinates for the space of DFs is…

Astrophysics of Galaxies · Physics 2021-08-11 Jun Yan Lau , James Binney

A given density matrix may be represented in many ways as a mixture of pure states. We show how any density matrix may be realized as a uniform ensemble. It has been conjectured that one may realize all probability distributions that are…

Quantum Physics · Physics 2009-11-07 Ingemar Bengtsson , Asa Ericsson

This is an improved version of the talk of the author given at the Antalya Algebra Days VII on May 21, 2005. We present an introduction to the theory of the invariants under the action of GL(n,C) by simultaneous conjugation of d matrices of…

Rings and Algebras · Mathematics 2007-05-23 Vesselin Drensky

Density Functional Theory (DFT) is a powerful and accurate tool exploited in Nuclear Physics to investigate the ground-state and some collective properties of nuclei along the whole nuclear chart. Models based on DFT are, however, not…

Nuclear Theory · Physics 2017-10-26 X. Roca-Maza , Y. F. Niu , G. Colò , P. F. Bortignon

We study the eigenvalue profile of concentration operators (multiplication by an indicator function followed by projection) acting on reproducing kernel Hilbert spaces. The spectral profile of such operators provides a useful notion of…

Spectral Theory · Mathematics 2026-04-09 Felipe Marceca , José Luis Romero , Michael Speckbacher , Lisa Valentini

Calculating perturbation response properties of materials from first principles provides a vital link between theory and experiment, but is bottlenecked by the high computational cost. Here a general framework is proposed to perform density…

Computational Physics · Physics 2024-03-01 He Li , Zechen Tang , Jingheng Fu , Wen-Han Dong , Nianlong Zou , Xiaoxun Gong , Wenhui Duan , Yong Xu

Based on ideas of R.W. Cross, a simplified proof is presented of the density invariance of certain operational quantities associated with bounded linear operators in normed vector spaces.

Functional Analysis · Mathematics 2007-05-23 Michael K. Kinyon

In this paper we derive an explicit formula for calculating the marginal likelihood of a given factorization of a categorical dataset. Since the marginal likelihood is proportional to the posterior probability of the factorization, these…

Machine Learning · Computer Science 2021-05-19 Anthony LaTorre

This paper aims at presenting a few models of quantum dynamics whose description involves the analysis of random unitary matrices for which dynamical localization has been proven to hold. Some models come from physical approximations…

Mathematical Physics · Physics 2011-05-03 Alain Joye

We shall say that a densely defined closed operator $T$ on a Hilbert space is balanced if $\cD(T)=\cD(T^*)$. Balanced operators are described in terms of their phase operators abnd their moduli. Examples of balanced operators are developed.…

Functional Analysis · Mathematics 2021-03-15 Konrad Schmüdgen

A growing body of research on probabilistic programs and causal models has highlighted the need to reason compositionally about model classes that extend directed graphical models. Both probabilistic programs and causal models define a…

Programming Languages · Computer Science 2023-12-15 Eli Sennesh , Jan-Willem van de Meent

Some new trace inequalities for operators in Hilbert spaces are provided. The superadditivity and monotonicity of some associated functionals are investigated and applications for power series of such operators are given. Some trace…

Functional Analysis · Mathematics 2014-09-24 Silvestru Sever Dragomir

The idea underlying the modal formulation of density-based clustering is to associate groups with the regions around the modes of the probability density function underlying the data. This correspondence between clusters and dense regions…

Social and Information Networks · Computer Science 2021-01-22 Giovanna Menardi , Domenico De Stefano

Let $M$ be a $B$-probability space. Assume that $B$ itself is a $D$-probability space; then $M$ can be viewed as $D$-probability space as well. Let $X$ be in $M$. We look at the question of relating the properties of $X$ as $B$-valued…

Operator Algebras · Mathematics 2007-05-23 Alexandru Nica , Dimitri Shlyakhtenko , Roland Speicher