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Several machine learning models are defined for inputs of any size, such as graphs with different numbers of nodes and point clouds containing varying numbers of points. The universality properties of such any-dimensional models remain…

Machine Learning · Computer Science 2026-05-25 Shengtai Yao , Eitan Levin , Mateo Díaz

We investigate the open dynamics of a quantum system when it is rapidly repeatedly updated by a quantum channel. Specifically, we analyze when this dynamics can purify the system. We develop a necessary and sufficient condition for such…

Quantum Physics · Physics 2017-04-19 Daniel Grimmer , Robert B. Mann , Eduardo Martin-Martinez

We provide theory, algorithms, and simulations of non-equilibrium quantum systems using a one-dimensional (1D) completely-positive (CP), matrix-product (MP) density-operator ($\rho$) representation. By generalizing the matrix product…

Quantum Physics · Physics 2025-09-16 Amit Jamadagni , Eugene Dumitrescu

We calculate universal finite-size scaling functions for systems with an n-component order parameter and algebraically decaying interactions. Just as previously has been found for short-range interactions, this leads to a singular…

Statistical Mechanics · Physics 2009-10-31 Erik Luijten

In the study of quantum computation, data is represented in terms of linear operators which form a generalized model of probability, and computations are most commonly described as products of unitary transformations, which are the…

Quantum Physics · Physics 2008-12-16 Jonathan Robert Niel de Beaudrap

By modeling the interaction of an open quantum system with its environment through a natural generalization of the classical concept of continuous time random walk, we derive and characterize a class of non-Markovian master equations whose…

Quantum Physics · Physics 2018-01-31 Adrián A. Budini

In quantum mechanics, wave functions and density matrices represent our knowledge about a quantum system and give probabilities for the outcomes of measurements. If the combined dynamics and measurements on a system lead to a density matrix…

Quantum Physics · Physics 2016-12-07 D. Tan , M. Naghiloo , K. Mølmer , K. W. Murch

A general structure of unitary evolution (evaporation) of the black hole, respecting causality imposed by the event horizon (semicausality), has been derived and presented in the language of quantum circuits. The resulting consequences for…

General Relativity and Quantum Cosmology · Physics 2024-04-25 Bogusław Broda

A fundamental task in quantum information science is to measure nonlinear functionals of quantum states, such as $\mathrm{Tr}(\rho^k O)$. Intuitively, one expects that computing a $k$-th order quantity generally requires $O(k)$ copies of…

Quantum Physics · Physics 2025-09-03 Yukun Zhang , Yusen Wu , You Zhou , Xiao Yuan

It is shown how all the major conceptual difficulties of standard (textbook) quantum mechanics, including the two measurement problems and the (supposed) nonlocality that conflicts with special relativity, are resolved in the consistent or…

Quantum Physics · Physics 2014-07-01 Robert B. Griffiths

Quantum impurities can host exotic many-body states that serve as sensitive probes of bath correlations. However, quantitative and non-perturbative methods for determining impurity thermodynamics in such settings remain scarce. Here, we…

Strongly Correlated Electrons · Physics 2026-01-09 Tao Yang , Z. Y. Xie , Rui Wang , Baigeng Wang

A critical question for the field of quantum computing in the near future is whether quantum devices without error correction can perform a well-defined computational task beyond the capabilities of state-of-the-art classical computers,…

Quantum computing, with its potential to enhance various machine learning tasks, allows significant advancements in kernel calculation and model precision. Utilizing the one-class Support Vector Machine alongside a quantum kernel, known for…

A software product line models the variability of highly configurable systems. Complete exploration of all valid configurations (the configuration space) is infeasible as it grows exponentially with the number of features in the worst case.…

Quantum Physics · Physics 2023-07-28 Joshua Ammermann , Tim Bittner , Domenik Eichhorn , Ina Schaefer , Christoph Seidl

The correlation structure of multitime quantum processes - succinctly described by quantum combs - is an important resource for many quantum information protocols and control tasks. Inspired by approaches for quantum states, we introduce…

Quantum Physics · Physics 2025-10-17 Graeme D. Berk , Kavan Modi , Simon Milz

Recovery of an $N$-dimensional, $K$-sparse solution $\mathbf{x}$ from an $M$-dimensional vector of measurements $\mathbf{y}$ for multivariate linear regression can be accomplished by minimizing a suitably penalized least-mean-square cost…

Information Theory · Computer Science 2019-10-29 Mohammad Ramezanali , Partha P. Mitra , Anirvan M. Sengupta

Manin, Feynman, and Deutsch have viewed quantum computing as a kind of universal physical simulation procedure. Much of the writing about quantum logic circuits and quantum Turing machines has shown how these machines can simulate an…

Quantum Physics · Physics 2007-10-22 Willem Fouche' , Johannes Heidema , Glyn Jones , Petrus H. Potgieter

We summarize recent work showing that the $1/r^2$ model of interacting particles in 1-dimension is a universal Hamiltonian for quantum chaotic systems. The problem is analyzed in terms of random matrices and of the evolution of their…

Condensed Matter · Physics 2025-07-04 B. Sriram Shastry

This thesis synthesizes probability and entropic inference with Quantum Mechanics (QM) and quantum measurement [1-6]. It is shown that the standard and quantum relative entropies are tools designed for the purpose of updating probability…

Quantum Physics · Physics 2018-04-25 Kevin Vanslette

Standard quantum mechanics is an idealisation based on infinite-precision objects: point states, exact probabilities, and sharp measurements. Yet every real experiment has finite resolution, and for macroscopic systems we never have access…

Quantum Physics · Physics 2026-05-29 Abbas Edalat