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Gaussian processes (GP) are Bayesian non-parametric models that are widely used for probabilistic regression. Unfortunately, it cannot scale well with large data nor perform real-time predictions due to its cubic time cost in the data size.…

Machine Learning · Statistics 2013-05-27 Jie Chen , Nannan Cao , Kian Hsiang Low , Ruofei Ouyang , Colin Keng-Yan Tan , Patrick Jaillet

We derive the self-consistent random phase approximations (sc-RPA) from the projective truncation approximation (PTA) for the equation of motion of two-time Green's function. The obtained sc-RPA applies to arbitrary temperature and recovers…

Strongly Correlated Electrons · Physics 2026-04-21 Yue-Hong Wu , Xinguo Ren , Ning-Hua Tong

Random Phase Approximation (RPA) is the theory most commonly used to describe the excitations of many-body systems. In this article, the secular equations of the theory are obtained by using three different approaches: the equation of…

Nuclear Theory · Physics 2023-03-14 Giampaolo Co'

The Particle Number Projected Generator Coordinate Method is formulated for the pairing Hamiltonian in a detailed way in the projection after variation and the variation after projection methods. The dependence of the wave functions on the…

Superconductivity · Physics 2009-11-11 M. A. Fernandez , J. L. Egido

The Platonic Representation Hypothesis suggests that independently trained neural networks converge to increasingly similar latent spaces. However, current strategies for mapping these representations are inherently pairwise, scaling…

We revisit the two derivations of the PBE correlation functional: The real-space cut-off of the exchange-correlation hole and the imposition of exact conditions. These differ in the Lieb-Simon limit, exemplified by the scaling of neutral…

Materials Science · Physics 2018-08-13 Antonio Cancio , Guo P. Chen , Brandon T. Krull , Kieron Burke

LibRPA is a software package designed for efficient calculations of random phase approximation (RPA) electron correlation energies from first principles using numerical atomic orbital (NAOs). Leveraging a localized resolution of identity…

Materials Science · Physics 2024-07-30 Rong Shi , Min-Ye Zhang , Peize Lin , Lixin He , Xinguo Ren

We introduce a relax-and-round approach embedding the quantum approximate optimization algorithm (QAOA) with $p\geq 1$ layers. We show for many problems, including Sherrington-Kirkpatrick spin glasses, that at $p=1$, it is as accurate as…

Quantum Physics · Physics 2024-01-25 Maxime Dupont , Bhuvanesh Sundar

Approximate counting via correlation decay is the core algorithmic technique used in the sharp delineation of the computational phase transition that arises in the approximation of the partition function of anti-ferromagnetic two-spin…

Computational Complexity · Computer Science 2019-02-04 Ivona Bezakova , Andreas Galanis , Leslie Ann Goldberg , Heng Guo , Daniel Stefankovic

In this paper, we show that the adaptive projected subgradient method (APSM) is bounded perturbation resilient. To illustrate a potential application of this result, we propose a set-theoretic framework for MIMO detection, and we devise…

Signal Processing · Electrical Eng. & Systems 2023-05-10 Jochen Fink , Renato L. G. Cavalcante , Slawomir Stanczak

A generalized version of the rotating-wave approximation for the single-mode spin-boson Hamiltonian is presented. It is shown that performing a simple change of basis prior to eliminating the off-resonant terms results in a significantly…

Quantum Physics · Physics 2009-11-13 E. K. Irish

Low-rank adaptation (LoRA) is a parameter-efficient fine-tuning (PEFT) method widely used in large language models (LLMs). LoRA essentially describes the projection of an input space into a low-dimensional output space, with the…

Computation and Language · Computer Science 2025-10-28 Shiwei Li , Xiandi Luo , Haozhao Wang , Xing Tang , Ziqiang Cui , Dugang Liu , Yuhua Li , Xiuqiang He , Ruixuan Li

Grover's algorithm is a fundamental quantum algorithm that offers a quadratic speedup for the unstructured search problem by alternately applying physically implementable oracle and diffusion operators. In this paper, we reformulate the…

Quantum Physics · Physics 2025-12-15 Zhijian Lai , Dong An , Jiang Hu , Zaiwen Wen

In this study, we propose two schemes for uplink control channels based on non-contiguous complementary sequences (CSs) where the peak-to-average-power ratio (PAPR) of the resulting orthogonal frequency division multiplexing (OFDM) signal…

Information Theory · Computer Science 2019-04-03 Alphan Şahin , Rui Yang

We investigate the accuracy of the coherent potential approximation (CPA) for a one-dimensional array with nearest-neighbor interactions and a Gaussian distribution of fluctuations in the on-site potential. The CPA values of the integrated…

Disordered Systems and Neural Networks · Physics 2015-05-18 I. Avgin , D. L. Huber

We adapt the techniques of entanglement renormalization tensor networks to weakly interacting quantum field theories in the continuum. A key tool is "quantum circuit perturbation theory," which enables us to systematically construct…

High Energy Physics - Theory · Physics 2019-04-24 Jordan Cotler , M. Reza Mohammadi Mozaffar , Ali Mollabashi , Ali Naseh

This letter addresses the estimation of directions-of-arrival (DoA) by a sensor array using a sparse model in the presence of array calibration errors and off-grid directions. The received signal utilizes previously used models for unknown…

Signal Processing · Electrical Eng. & Systems 2019-06-04 Cheng-Yu Hung , Mostafa Kaveh

To improve the system throughput, this paper proposes a network non-orthogonal multiple access (N-NOMA) technique for the uplink coordinated multi-point transmission (CoMP). In the considered scenario, multiple base stations collaborate…

Information Theory · Computer Science 2018-09-25 Yanshi Sun , Zhiguo Ding , Xuchu Dai , Octavia A. Dobre

We present an operational procedure to transform global symmetries into local symmetries at the level of individual quantum states, as opposed to typical gauging prescriptions for Hamiltonians or Lagrangians. We then construct a compatible…

Quantum Physics · Physics 2015-03-05 Jutho Haegeman , Karel Van Acoleyen , Norbert Schuch , J. Ignacio Cirac , Frank Verstraete

In wavefunction-based $\textit{ab-initio}$ quantum mechanical calculations, achieving absolute convergence with respect to the one-electron basis set is a long-standing challenge. In this work, using the random phase approximation (RPA)…

Materials Science · Physics 2025-10-17 Hao Peng , Xinguo Ren