English
Related papers

Related papers: Susceptibility Formulation of Density Matrix Pertu…

200 papers

Automatic differentiation is an invaluable feature of machine learning and quantum machine learning software libraries. In this work it is shown how quantum automatic differentiation can be used to solve the condensed-matter problem of…

Quantum Physics · Physics 2022-11-29 Olivia Di Matteo , R. M. Woloshyn

Response calculations in density functional theory aim at computing the change in ground-state density induced by an external perturbation. At finite temperature these are usually performed by computing variations of orbitals, which involve…

Numerical Analysis · Mathematics 2023-04-04 Eric Cancès , Michael F. Herbst , Gaspard Kemlin , Antoine Levitt , Benjamin Stamm

We present several finite-temperature recursive Fermi-operator expansion schemes based on the second-order spectral projection (SP2) method. Our approach builds on a previous observation that the electronic structure problem, as formulated…

We present a {\sl non--perturbative} method, called {\sl Parametric Perturbation Theory} (PPT), which is alternative to the ordinary perturbation theory. The method relies on a principle of simplicity for the observable solutions, which are…

Other Condensed Matter · Physics 2007-05-23 Paolo Amore

This study proposes a low-complexity interpretable classification system. The proposed system contains three main modules including feature extraction, feature reduction, and classification. All of them are linear. Thanks to the linear…

Computer Vision and Pattern Recognition · Computer Science 2020-04-15 Tzu-Wei Tseng , Kai-Jiun Yang , C. -C. Jay Kuo , Shang-Ho , Tsai

Robustness is a key requirement for widespread deployment of machine learning algorithms, and has received much attention in both statistics and computer science. We study a natural model of robustness for high-dimensional statistical…

Machine Learning · Computer Science 2020-06-03 Pranjal Awasthi , Xue Chen , Aravindan Vijayaraghavan

We present an efficient perturbative method to obtain both static and dynamic polarizabilities and hyperpolarizabilities of complex electronic systems. This approach is based on the solution of a frequency dependent Sternheimer equation,…

Materials Science · Physics 2009-11-13 Xavier Andrade , Silvana Botti , Miguel A. L. Marques , Angel Rubio

We develop and analyze a fault-tolerant quantum algorithm for computing $n$-th order response properties necessary for analysis of non-linear spectroscopies of molecular and condensed phase systems. We use a semi-classical description in…

Quantum Physics · Physics 2024-04-23 Tyler Kharazi , Torin F. Stetina , Liwen Ko , Guang Hao Low , K. Birgitta Whaley

Weighted model integration (WMI) is a very appealing framework for probabilistic inference: it allows to express the complex dependencies of real-world hybrid scenarios where variables are heterogeneous in nature (both continuous and…

Artificial Intelligence · Computer Science 2019-10-01 Zhe Zeng , Fanqi Yan , Paolo Morettin , Antonio Vergari , Guy Van den Broeck

Two-parameter perturbation theory is a scheme tailor-made to consistently include nonlinear density contrasts on small scales ($<100\; \mathrm{Mpc}$), whilst retaining a traditional approach to cosmological perturbations in the…

General Relativity and Quantum Cosmology · Physics 2020-03-18 Christopher Gallagher , Timothy Clifton , Chris Clarkson

Interpretable classification of time series presents significant challenges in high dimensions. Traditional feature selection methods in the frequency domain often assume sparsity in spectral density matrices (SDMs) or their inverses, which…

Machine Learning · Statistics 2024-08-19 Sarbojit Roy , Malik Shahid Sultan , Hernando Ombao

Proximal causal learning is a promising framework for identifying the causal effect under the existence of unmeasured confounders. Within this framework, the doubly robust (DR) estimator was derived and has shown its effectiveness in…

Methodology · Statistics 2024-03-12 Yong Wu , Yanwei Fu , Shouyan Wang , Xinwei Sun

Recently, sophisticated deep learning-based approaches have been developed for generating efficient initial guesses to accelerate the convergence of density functional theory (DFT) calculations. While the actual initial guesses are often…

Chemical Physics · Physics 2026-03-24 Zhe Liu , Yuyan Ni , Zhichen Pu , Qiming Sun , Siyuan Liu , Wen Yan

In this paper we address the complexity of solving linear programming problems with a set of differential equations that converge to a fixed point that represents the optimal solution. Assuming a probabilistic model, where the inputs are…

Computational Complexity · Computer Science 2007-05-23 Asa Ben-Hur , Joshua Feinberg , Shmuel Fishman , Hava T. Siegelmann

In the Super-Transition-Array statistical method for the computation of radiative opacity of hot dense matter, the moments of the absorption or emission features involve partition functions with reduced degeneracies, occurring through the…

Atomic Physics · Physics 2024-05-14 Jean-Christophe Pain , Brian Wilson

Robustness analysis is an emerging field in the domain of uncertainty quantification. It consists of analysing the response of a computer model with uncertain inputs to the perturbation of one or several of its input distributions. Thus, a…

Statistics Theory · Mathematics 2020-12-16 Clement Gauchy , Jerome Stenger , Roman Sueur , Bertrand Iooss

We propose a fluctuation-dissipation theorem in open quantum systems from an information-theoretic perspective. We define the fidelity susceptibility that measures the sensitivity of the systems under perturbation and relate it to the…

Quantum Physics · Physics 2024-09-30 Jian-Hao Zhang , Cenke Xu , Yichen Xu

Let A and E be Hermitian self-adjoint matrices, where A is fixed and E a small perturbation. We study how the eigenvalues and eigenvectors of A+E depend on E, with the aim of obtaining first order formulas (and when possible also second…

Mathematical Physics · Physics 2019-08-26 Marcus Carlsson

Density regression provides a flexible strategy for modeling the distribution of a response variable $Y$ given predictors $\mathbf{X}=(X_1,\ldots,X_p)$ by letting that the conditional density of $Y$ given $\mathbf{X}$ as a completely…

Statistics Theory · Mathematics 2016-01-07 Weining Shen , Subhashis Ghosal

We develop a linear response framework for interpretability that treats a neural network as a Bayesian statistical mechanical system. A small perturbation of the data distribution, for example shifting the Pile toward GitHub or legal text,…

Machine Learning · Computer Science 2026-03-10 Garrett Baker , George Wang , Jesse Hoogland , Daniel Murfet