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Diffusion models generate data by learning to reverse a forward process, where samples are progressively perturbed with Gaussian noise according to a predefined noise schedule. From a geometric perspective, each noise schedule corresponds…

Image and Video Processing · Electrical Eng. & Systems 2025-10-21 Teng Zhang , Hongxu Jiang , Kuang Gong , Wei Shao

Despite the advances in the development of numerical methods analytical approaches still play the key role on the way towards a deeper understanding of many-particle systems. In this regards, diagonalization schemes for Hamiltonians…

Strongly Correlated Electrons · Physics 2020-10-15 Steffen Sykora , Arnd Hübsch , Klaus W. Becker

Several mean-field theories predict that Hessian matrices of amorphous solids can be written by using the random matrix in the limit of the large spatial dimensions $d\to\infty$. Motivated by these results, we here propose a way to map a…

Disordered Systems and Neural Networks · Physics 2022-08-31 Harukuni Ikeda , Masanari Shimada

In this work, we study some properties of the Hickson Compact Groups (HCGs) using N-body simulations for the Generalized Dark Matter (GDM) model, described by three free functions, the sound speed, the viscosity and the equation of state.…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-25 Jessica N. López-Sánchez , Erick Munive-Villa , Ana Avilez-López , Oscar M. Martínez-Bravo

Recent developments in the numerical renormalization group (NRG) allow the construction of the full density matrix (FDM) of quantum impurity models (see A. Weichselbaum and J. von Delft) by using the completeness of the eliminated states…

Strongly Correlated Electrons · Physics 2012-09-04 L. Merker , A. Weichselbaum , T. A. Costi

The Gaussian Process Convolution Model (GPCM; Tobar et al., 2015a) is a model for signals with complex spectral structure. A significant limitation of the GPCM is that it assumes a rapidly decaying spectrum: it can only model smooth…

Machine Learning · Statistics 2022-04-15 Wessel P. Bruinsma , Martin Tegnér , Richard E. Turner

We study quantum corrections to the $\Lambda$CDM model model arising from a minimum measurable length in Heisenberg's uncertainty principle. We focus on a higher-order Generalized Uncertainty Principle, beyond the quadratic form. This…

General Relativity and Quantum Cosmology · Physics 2025-12-25 Andronikos Paliathanasis , Genly Leon , Yoelsy Leyva , Giuseppe Gaetano Luciano , Amare Abebe

Kohn-Sham spin-density functional theory provides an efficient and accurate model to study electron-electron interaction effects in quantum dots, but its application to large systems is a challenge. An efficient algorithm for the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Hong Jiang , Harold U. Baranger , Weitao Yang

New inequalities for tomographic probability distributions and density matrices of qutrit states are obtained by means of generalization of qubit portrait method. The approach based on the qudit portrait method to get new entropic…

Quantum Physics · Physics 2019-02-12 V. N. Chernega , O. V. Man'ko , V. I. Man'ko

We present a universal technique for quantum state estimation based on the maximum-likelihood method. This approach provides a positive definite estimate for the density matrix from a sequence of measurements performed on identically…

Quantum Physics · Physics 2009-10-31 K. Banaszek , G. M. D'Ariano , M. G. A. Paris , M. F. Sacchi

The most general evolution of the density matrix of a quantum system with a finite-dimensional state space is by stochastic maps which take a density matrix linearly into the set of density matrices. These dynamical stochastic maps form a…

Quantum Physics · Physics 2009-11-07 E. C. G. Sudarshan , Anil Shaji

We propose a way of obtaining effective low energy Hubbard-like model Hamiltonians from ab initio Quantum Monte Carlo calculations for molecular and extended systems. The Hamiltonian parameters are fit to best match the ab initio two-body…

Strongly Correlated Electrons · Physics 2015-08-06 Hitesh J. Changlani , Huihuo Zheng , Lucas K. Wagner

We propose and implement an algorithm to calculate the norm and reduced density matrices of the antisymmetrized geminal power (AGP) of any rank with polynomial cost. Our method scales quadratically per element of the reduced density…

Chemical Physics · Physics 2020-05-14 Armin Khamoshi , Thomas Henderson , Gustavo Scuseria

The Density Matrix Renormalization Group (DMRG) method has become a prominent tool for simulating strongly correlated electronic systems characterized by dominant static correlation effects. However, capturing the full scope of electronic…

Chemical Physics · Physics 2024-11-13 Nicholas Bauman , Libor Veis , Karol Kowalski , Jiri Brabec

A Gaussian operator representation for the many body density matrix of fermionic systems, developed by Corney and Drummond [Phys. Rev. Lett, v93, 260401 (2004)], is used to derive approximate decoupling schemes for their dynamics. In this…

Other Condensed Matter · Physics 2009-06-01 Saar Rahav , Shaul Mukamel

The technique of density matrix equation (DME) for a small system interacting with a bath is explained in detail. Special attention is given to the nonsecular DME that is needed in the vicinity of overdamped tunnelling resonances in…

Statistical Mechanics · Physics 2012-02-22 D. A. Garanin

The density matrix renormalization group (DMRG) is a numerical method that optimizes a variational state expressed by a tensor product. We show that the ground state is not fully optimized as far as we use the standard finite system…

Statistical Mechanics · Physics 2010-05-20 H. Takasaki , T. Hikihara , T. Nishino

Density Matrix Renormalization Group (DMRG) algorithm has been extremely successful for computing the ground states of one-dimensional quantum many-body systems. For problems concerned with mixed quantum states, however, it is less…

Strongly Correlated Electrons · Physics 2022-06-01 Chu Guo

Mammography is the most commonly used imaging modality for breast cancer screening, driving an increasing demand for deep-learning techniques to support large-scale analysis. However, the development of accurate and robust methods is often…

Image and Video Processing · Electrical Eng. & Systems 2025-07-28 Xin Li , Kaixiang Yang , Qiang Li , Zhiwei Wang

We present the Gaussian process density sampler (GPDS), an exchangeable generative model for use in nonparametric Bayesian density estimation. Samples drawn from the GPDS are consistent with exact, independent samples from a distribution…

Computation · Statistics 2009-12-25 Ryan Prescott Adams , Iain Murray , David J. C. MacKay
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