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Related papers: Green's Functions from Quantum Cluster Algorithms

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Efficient computation of lattice defect geometries such as point defects, dislocations, disconnections, grain boundaries, interfaces and free surfaces requires accurate coupling of displacements near the defect to the long-range elastic…

Materials Science · Physics 2013-08-06 Joseph A. Yasi , Dallas R. Trinkle

This paper proposes a hybrid quantum-classical algorithm that learns a suitable quantum feature map that separates unlabelled data that is originally non linearly separable in the classical space using a Variational quantum feature map and…

Quantum Physics · Physics 2021-12-14 Arvind S Menon , Nikaash Puri

Recently, general point interactions in one dimension has been used to model a large number of different phenomena in quantum mechanics. Such potentials, however, requires some sort of regularization to lead to meaningful results. The usual…

Quantum Physics · Physics 2009-11-07 Alexandre G. M. Schmidt , Bin Kang Cheng , Marcos G. E. da Luz

Recent work on the quantization of Maxwell theory has used a non-covariant class of gauge-averaging functionals which include explicitly the effects of the extrinsic-curvature tensor of the boundary, or covariant gauges which, unlike the…

High Energy Physics - Theory · Physics 2008-02-03 Giampiero Esposito

We initiate the systematic study of experimental quantum physics from the perspective of computational complexity. To this end, we define the framework of quantum algorithmic measurements (QUALMs), a hybrid of black box quantum algorithms…

Quantum Physics · Physics 2022-03-09 Dorit Aharonov , Jordan Cotler , Xiao-Liang Qi

Projective measurements with high quantum efficiency is often assumed to be required for efficient circuit based quantum computing. We argue that this is not the case and show that this fact has actually be known previously though not…

Quantum Physics · Physics 2015-03-17 A. P. Lund

This report provides Green's functions (classical propagators) of gravitational fields appearing in general relativity. The existence of Green's function of the wave equation in curved space with an indefinite metric is ensured owing to the…

General Relativity and Quantum Cosmology · Physics 2025-02-21 Yoshimasa Kurihara

The nonequilibrium Green's function formalism provides a versatile and powerful framework for numerical studies of nonequilibrium phenomena in correlated many-body systems. For calculations starting from an equilibrium initial state, a…

Strongly Correlated Electrons · Physics 2024-07-11 Matthias Murray , Hiroshi Shinaoka , Philipp Werner

A simple model of noninteracting electrons with a separable one-body potential is used to discuss the possible pole structure of single particle Green's functions for fermions on unphysical sheets in the complex frequency plane as a…

Strongly Correlated Electrons · Physics 2009-10-30 K. Schoenhammer

Green's function provides an inherent connection between theoretical analysis and numerical methods for elliptic partial differential equations, and general absence of its closed-form expression necessitates surrogate modeling to guide the…

Numerical Analysis · Mathematics 2025-09-16 Qi Sun , Shengyan Li , Bowen Zheng , Lili Ju , Xuejun Xu

Amplitude estimation algorithms are based on Grover's algorithm: alternating reflections about the input state and the desired outcome. But what if we are given the ability to perform arbitrary rotations, instead of just reflections? In…

Quantum Physics · Physics 2023-03-08 Patrick Rall , Bryce Fuller

We perform the two loop level renormalization of quantum gravity in $2+\epsilon$ dimensions. We work in the background gauge whose manifest covariance enables us to use the short distance expansion of the Green's functions. We explicitly…

High Energy Physics - Theory · Physics 2009-10-30 Toshiaki Aida , Yoshihisa Kitazawa

Variational algorithms are a promising paradigm for utilizing near-term quantum devices for modeling electronic states of molecular systems. However, previous bounds on the measurement time required have suggested that the application of…

The method of generating functional is generalized to the case of strongly correlated systems, and applied to the Hubbard model. For the electronic Green's function constructed for Hubbard operators, an equation using variational…

Strongly Correlated Electrons · Physics 2007-05-23 Yu. A. Izyumov , N. I. Chaschin , D. S. Alexeev , F. Mancini

Cluster analysis methods seek to partition a data set into homogeneous subgroups. It is useful in a wide variety of applications, including document processing and modern genetics. Conventional clustering methods are unsupervised, meaning…

Methodology · Statistics 2014-07-11 Eric Bair

Many clustering schemes are defined by optimizing an objective function defined on the partitions of the underlying set of a finite metric space. In this paper, we construct a framework for studying what happens when we instead impose…

Machine Learning · Statistics 2010-12-01 Gunnar Carlsson , Facundo Memoli

We present the analytical solution in closed form for the semiclassical limit of the quantum mechanical Coulomb Green function in position space in n dimensions. We utilize a projection method which has its roots in Lambert's theorem and…

Quantum Physics · Physics 2009-07-05 Vassiliki Kanellopoulos , Manfred Kleber , Tobias Kramer

Clustering is one of the fundamental tasks in data analytics and machine learning. In many situations, different clusterings of the same data set become relevant. For example, different algorithms for the same clustering task may return…

Optimization and Control · Mathematics 2020-04-06 Steffen Borgwardt , Charles Viss

The two-point gauge-invariant correlation function of gluonic field strengths, which is the main input in the stochastic vacuum model, is derived by using its relation to the Green functions of one- and two-gluon gluelumps. These Green…

High Energy Physics - Phenomenology · Physics 2009-11-11 Dmitri Antonov

This article is a short introduction to and review of the cluster-state model of quantum computation, in which coherent quantum information processing is accomplished via a sequence of single-qubit measurements applied to a fixed quantum…

Quantum Physics · Physics 2009-11-11 Michael A. Nielsen