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We present the spectral analysis of a one-dimensional Hubbard model with a parabolic potential, using a real-space cluster perturbation theory (rCPT) designed to study spatially inhomogeneous electron systems with strong correlation. It is…

Strongly Correlated Electrons · Physics 2025-07-31 Kaito Matsuki , Chisa Hotta , Kenichi Asano

The semi-empirical INDO/s method is popular for studies of excitation energies and absorption of molecules due to its low computational requirement, making it possible to make predictions for large systems. However, its accuracy is…

Mesoscale and Nanoscale Physics · Physics 2025-12-12 Ezekiel Oyeniyi , Omololu Akin-Ojo

Direct air capture (DAC) of carbon dioxide is a promising method for mitigating climate change. Solid sorbents, such as metal-organic frameworks, are currently being tested for DAC application. However, their potential for deployment at…

Quantum Physics · Physics 2024-12-05 Marco Antonio Barroca , Rodrigo Neumann Barros Ferreira , Mathias Steiner

Purpose: To develop a model-based deep neural network for high-quality image reconstruction of undersampled multi-coil chemical exchange saturation transfer (CEST) data. Theory and Methods: Inspired by the variational network, the CEST…

Medical Physics · Physics 2023-05-26 Jianping Xu , Tao Zu , Yi-Cheng Hsu , Xiaoli Wang , Kannie W. Y. Chan , Yi Zhang

We study photoabsorption reaction and real Compton scattering (RCS) within the color dipole model. We rely on a photon wave function derived in the instanton vacuum model, and on the energy dependent phenomenological elastic dipole…

High Energy Physics - Phenomenology · Physics 2009-09-24 B. Z. Kopeliovich , Ivan Schmidt , M. Siddikov

The projection-based quantum embedding method is applied to electronically excited states of valence, Rydberg, and charge-transfer character, valence- and core-ionized states, as well as bound and temporary radical anions. We embed…

Chemical Physics · Physics 2021-06-10 Valentina Parravicini , Thomas-C. Jagau

We describe the Monte Carlo (MC) simulation package of the `2K-CAPTURE' setup and discuss the agreement of its output with data. The `2K-CAPTURE' MC simulates the energy loss of particles in detector and components of the passive shield and…

Exascale computing promises quantities of data too large to efficiently store and transfer across networks in order to be able to analyze and visualize the results. We investigate Compressive Sensing (CS) as a way to reduce the size of the…

Information Theory · Computer Science 2015-08-27 Maher Salloum , Nathan Fabian , David M. Hensinger , Jeremy A. Templeton

Real-time time-dependent density functional theory (RT-TDDFT) can in principle access the whole absorption spectrum of a many-electron system exposed to a narrow pulse. However, this requires an accurate and efficient propagator for the…

Chemical Physics · Physics 2024-06-19 Linfeng Ye , Hao Wang , Yong Zhang , Wenjian Liu

Coupled-cluster theory with single, double, and perturbative triple excitations (CCSD(T)) -- often considered the "gold standard" of main-group quantum chemistry -- is inapplicable to three-dimensional metals due to an infrared divergence,…

Materials Science · Physics 2023-03-21 Verena A. Neufeld , Timothy C. Berkelbach

Offline reinforcement learning (RL) aims to learn an effective policy from a pre-collected dataset. Most existing works are to develop sophisticated learning algorithms, with less emphasis on improving the data collection process. Moreover,…

Machine Learning · Computer Science 2023-12-20 Chenyu Sun , Hangwei Qian , Chunyan Miao

Simulations of electrochemical double layer capacitors based on porous carbon electrodes, energy storage systems which accumulate and release energy through reversible ion adsorption at electrode/electrolyte interfaces, are often performed…

Materials Science · Physics 2026-03-25 El Hassane Lahrar , Mathieu Salanne , Rudolf Weeber , Céline Merlet

We derive the two-time linear response theory for out-of-equilibrium pumped systems, generic pump-probe delays and probe frequencies. Such a theory enormously simplifies the numerical calculations, for instance, of the optical conductivity…

Optics · Physics 2024-12-10 Amir Eskandari-asl , Adolfo Avella

Compressed sensing (CS) is a powerful method routinely employed to accelerate image acquisition. It is particularly suited to situations when the image under consideration is sparse but can be sampled in a basis where it is non-sparse. Here…

Image and Video Processing · Electrical Eng. & Systems 2022-07-18 Xudong Lv , Ashok Ajoy

Compressive sensing (CS) is a technique that enables the recovery of sparse signals using fewer measurements than traditional sampling methods. To address the computational challenges of CS reconstruction, our objective is to develop an…

Image and Video Processing · Electrical Eng. & Systems 2024-01-08 Youhao Yu , Richard M. Dansereau

A new approach has been used to explain the experimental data for the $^{12}$C+$^{12}$C system over a wide energy range in the laboratory system from 32.0 MeV to 126.7 MeV. This new coupled-channels based approach involves replacing the…

Nuclear Theory · Physics 2009-11-07 I. Boztosun , W. D. M. Rae

Various studies that address the compressed sensing problem with Multiple Measurement Vectors (MMVs) have been recently carried. These studies assume the vectors of the different channels to be jointly sparse. In this paper, we relax this…

Machine Learning · Computer Science 2016-11-14 Hamid Palangi , Rabab Ward , Li Deng

We present a real-space method for computing the random phase approximation (RPA) correlation energy within Kohn-Sham density functional theory, leveraging the low-rank nature of the frequency-dependent density response operator. In…

Computational Physics · Physics 2025-04-03 Boqin Zhang , Shikhar Shah , John E. Pask , Edmond Chow , Phanish Suryanarayana

We propose two ways of estimating the current source density (CSD) from measurements of voltage on a Cartesian grid with missing recording points using the inverse CSD method. The simplest approach is to substitute local averages (LA) in…

Quantitative Methods · Quantitative Biology 2009-03-16 Daniel K. Wojcik , Szymon Leski

In this work, we extend selected configuration interaction (SCI) methods beyond energies and expectation values by introducing a linear response (LR) framework for molecular response properties. Existing SCI approaches are capable of…

Chemical Physics · Physics 2025-11-24 Peter Reinholdt , Erik Kjellgren , Jacob Kongsted